FINAL REPORT

ESTUARY INVENTORY PROJECT OREGON

PROJECT TITLE: Techn ica l a s i s s t a n c e t o l o c a l p l a n n i n g s t a f f s i n f u l f i l l i n g t h e requ i rements o f t h e LCDC e s t u a r i n e resources g o a l .

JOB TITLE: H a b i t a t c l a s s i f i c a t i o n and i n v e n t o r y methods f o r t h e management o f Oregon e s t u a r i e s .

PROJECT PERIOD: February 1978 - June 1979

Prepared by: Dan Bottom Becky Kreag Frank R a t t i Cyndi Roye R i c k S t a r r

P r o j e c t e d i t o r : P h i l i p Howel l

Oregon Department o f F i s h and W i l d l i f e 506 S . W . M i l l S t r e e t P . 0 . Box 3503 P o r t l and , Oregon 97208

The p r e p a r a t i o n o f t h i s document was f i nanced i n p a r t by funds from t h e Oregon Land C o n s e r v a t i o n and Development Department and t h e O f f i c e o f Coasta l Zone Management, N a t i o n a l Oceanic and Atmospher ic A d m i n i s t r a t i o n , U . S . Department o f Commerce, and by t h e Oregon Department o f F i s h and W i l d l i f e .

PREFACE

On December 8, 1976, the Oregon Land Conservation and Development I Commi ss ion (LCDC) adopted the Estuarine Resources Goal, one of four planning

goals specifically concerned with Oregon's coastal zone. The goal requires

that coastal cities and counties establish policies for the conservation and

development of estuarine resources as part of their comprehensive land and

water use plans. In order to fulfill the goal, local jurisdictions must first

complete inventories of the physical, social, and economic resources of each

estuary "in sufficient detail to establish a sound basis for estuarine manage-

ment and to enable the identification of areas for preservation and areas of

exceptional potential for development" (LCDC 197713).

In February, 1978, the Oregon Department of Fish and Wildlife (ODFW)

received a grant from LCDC to assist local jurisdictions in completing the

resource inventory requirements of the Estuarine Resources Goal. The project I

had two primary objectives:

(I) To assemble biological and physical data for selected Oregon estuaries,

(2) To identify data gaps and suggest future research needed for planning

and management of each estuary.

In meeting these two objectives, ODFW has provided several types of

information, including the material presented in this series of reports. This

report is a general introduction to the methods and study design of the

technical assistance project, as well as a guide to collecting and organizing

I resource information for planning. It is also intended to be a reference for

the other reports published in this series.

This volume is divided into two parts. Part 1 discusses estuary and

estuarine habitat classification as a basis for resource planning. A hier-

archical classification system is presented and suggested as an appropriate

i

system f o r Oregon e s t u a r i e s . P a r t 2 o f t h e r e p o r t suggests g u i d e l i n e s f o r

e s t u a r i n e resource i n v e n t o r i e s , i n c l u d i n g a l i s t o f s p e c i f i c c a t e g o r i e s o f

d a t a and methods o f da ta c o l l e c t i o n most needed f o r p l a n n i n g . The g u i d e l i n e s

a r e a l s o p resen ted as a c h e c k l i s t f o r i d e n t i f y i n g research needs f o r e s t u a r i e s

where these d a t a a r e n o t c u r r e n t l y a v a i l a b l e .

Volume 2 i n t h i s s e r i e s c o n s i s t s o f s e v e r a l r e p o r t s summarizing c u r r e n t

p h y s i c a l and b i o l o g i c a l d a t a and d e s c r i b i n g t h e h a b i t a t s f o r s e l e c t e d Oregon

e s t u a r i e s . S p e c i f i c management and research recommendations a r e d iscussed i n

each e s t u a r y r e p o r t . E s t u a r i e s w i t h o u t a p r e v i o u s l y completed p l a n n i n g inven-

t o r y o r w i t h s p e c i a l p l a n n i n g needs were g i v e n p r i o r i t y f o r these r e p o r t s .

T a b l e i summarizes t h e i n f o r m a t i o n compi led d u r i n g t h i s p r o j e c t . I n

a d d i t i o n t o t h e separa te e s t u a r y r e p o r t s i n volume 2 , we have c o l l e c t e d data

and c l a s s i f i e d h a b i t a t s i n 16 Oregon e s t u a r i e s as d e s c r i b e d b e l o w :

Data Notebooks

ODFW pho tocop ied and assembled i n notebooks a v a i l a b l e p h y s i c a l and

b i o l o g i c a l d a t a f o r each o f 15 Oregon e s t u a r i e s . The i n f o r m a t i o n was o rgan ized

by s u b j e c t a c c o r d i n g t o t h e data c a t e g o r i e s i n t h e i n v e n t o r y g u i d e l i n e s

d e s c r i b e d i n P a r t 2 o f t h i s r e p o r t . The notebooks se rve as a t e c h n i c a l

r e f e r e n c e t o t h e e x i s t i n g resource d a t a f o r each e s t u a r y . The notebooks a r e

o rgan ized so t h a t a d d i t i o n a l i n f o r m a t i o n can be added as new research i s

completed. A complete s e t o f t h e notebooks i s on f i l e w i t h LDCD, Salem,

i n e H a b i t a t Maps

each o f t h e e s t u a r i e s i n Tab le i, i n t e r t i d a l and s u b t i d a l h a b i t a t s

u s i n g a m o d i f i e d v e r s i o n o f a U .S . F i s h and W i l d l i f e S e r v i c e

s t u a r i n e h a b i t a t c l a s s i f i c a t i o n system. T h e system i s d e s c r i b e d i n

. . I I

d e t a i l i n P a r t 1 o f t h i s r e p o r t . H a b i t a t s were d e l i n e a t e d by a numer ica l code

on base maps a t sca les r a n g i n g from 1:12,000 t o 1:24,000. F u l l s c a l e c o p i e s

o f t h e h a b i t a t maps may be o b t a i n e d from ODFW, Research and Development Sect ion,

C o r v a l l i s , Oregon.

Tab le i . Products a v a i l a b l e f o r each e s t u a r y s t u d i e d d u r i n g t h e ODFW t e c h n i c a l a s s i s t a n c e p r ~ j e c t . ~

Resource I n v e n t o r y Data Notebook H a b i t a t Map Report

Necan i cum X X Nehal em X X T i l lamook b X N e t a r t s X X X Sand Lake X X X Nestucca X X X Salmon R i v e r X X S i l e t z X X X Yaquina X X A l sea X X c Sius law X X Umpqua X X X Coos X X X Coqui l l e X X X Rogue X X X Chetco X X X

a Estuaries for which the information is available are shown by "x". A notebook was not completed for Tillamook Bay because Tillamook County planners had already compiled a similar reference.

C Brief summary and planning recommendations are available for the Alsea estuary, but are not included among this series of reports.

i i i

ACKNOWLEDGEMENTS

The reports in this series are the result of the hard work of a large

number of individuals whom the authors most gratefully acknowledge. We are

especially indebted to Neal Coenen of LCDC for his enthusiastic support and

guidance throughout the course of this project.

We wish to thank Dennis Peters and USFWS for granting us permission

to use their habitat classification system as a basis for our work. We

also appreciate the financial assistance of the Natural Area Preserves

Advisory Committee (NAPAC) which allowed us to complete final revisions

and habitat definitions for our estuarine classification system. Our

thanks to Bob Frenkel and Jeff Goner of NAPAC for their suggestions con-

cerning the classification system.

* Many individuals from ODFW spent long hours reviewing numerous drafts

in this report series. We are especially grateful to our editor, Phil Howell,

whose talents have greatly enhanced the quality of all the final reports. We

! are indebted to Jim Lauman, Jim Lichatowich, A1 McGie, and Dale Snow for their I

suggestions and comments. We also wish to thank the following ODFW district

reports: Reese Bender, Dave Heckeroth, Jim Hutchison, John Johnson, Warren

Knispel, Al Mirati, Bill Mullarkey, Rik Riikula, Gene Stewart, Harold Sturgis,

Doug Taylor, and John Thiebes.

Our thanks also to Marita Loch for her assistance with graphics and to

Ernie Whited who spent months drafting all the habitat maps. We appreciate

the time and talent donated by Harold Smith in designing our report covers.

typing many drafts under a very tight time schedule we also send thanks to

We must r e s e r v e a v e r y s p e c i a l thank you f o r two i n d i v i d u a l s who

s t e a d f a s t l y and e n t h u s i a s t i c a l l y encouraged o u r work t h e p a s t 18 months. We

deeply a p p r e c i a t e t h e suppor t and ideas o f f e r e d by H a r r y Wagner and

J i m L i c h a t o w i c h th roughou t t h i s p r o j e c t .

CONTENTS

PREFACE ................................................................ ........................................................ ACKNOWLEDGEMENTS

P a r t I - E s t u a r y and E s t u a r i n e H a b i t a t C l a s s i f i c a t i o n

INTRODUCTION ............................................................ ................................... CRITERIA FOR ESTUARINE CLASSIFICATION

. ............................ PHYSICAL CLASSIFICATION OF OREGON ESTUARIES P h y s i o g r a p h i c Prov inces ............................................

The Coast Range ............................................... The Klamath Mountains .........................................

...................................................... Geomorphology Drowned r i v e r v a l l e y e s t u a r i e s ................................

............................................... B l i n d e s t u a r i e s B a r - b u i l t E s t u a r i e s ...........................................

. . . . . . . . . . . . . . . . . . . . . . . . . . . Dra inage Area vs . E s t u a r i n e Sur face Area . ............................................ OREGON ESTUARINE SUBSYSTEMS

Mar ine Subsystem ................................................... ...................................................... Bay Subsystem

Slough Subsystem ................................................... R i v e r i n e Subsystem .................................................

.......................... OREGON ESTUARINE HABITAT CLASSIFICATION SYSTEM T i d a l Regime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H a b i t a t Classes Unconso l ida ted b o t t o m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rock bot tom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A q u a t i c bed ( i n t e r t i d a l and s u b t i d a l ) . . . ......................

......................................................... Shore - F l a t .......................................................... - Beach/bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T i d a l marsh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ESTUARY CLASSIFICATION AND THE LCOC ESTUARINE RESOURCES GOAL . . . . . . . . . . . .

Page

P a r t I I . Resource I n v e n t o r i e s f o r Es tuary P l a n n i n g and Management

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INTRODUCTION 57 . .......................................... RESOURCE INVENTORY GUIDELINES 58

I n v e n t o r y o f P h y s i c a l C h a r a c t e r i s t i c s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 I n v e n t o r y o f B i o l o g i c a l C h a r a c t e r i s t i c s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RESEARCH NEEDS FOR OREGON ESTUARIES 60 ........................................... P h y s i c a l C h a r a c t e r i s t i c s 61 . .......................................... P h y s i c a l d imensions 61

H y d r o l o g i c a l c h a r a c t e r i s t i c s .................................. 63 Watgr ................................................ 64

..................................................... Sediments 65 . . ....................................... B i o l o g i c a l C h a r a c t e r i s t i c s 65

. ........................................................ Algae 65 - ....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seagrasses 68 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T i d a l marshes 68

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Zoop lank ton and i n v e r t e b r a t e s F i s h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B i r d s and mammals

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Research P r i o r i t i e s

LITERATURE CITED ........................................................ Appendix A . OREGON ESTUARINE HABITAT CLASSIFICATION SYSTEM . . . . . . . . . . . . . Appendix T a b l e 8 . Data needed t o d e s c r i b e t h e p h y s i c a l and chemica l

................................ c h a r a c t e r i s t i c s o f Oregon e s t u a r i e s Appendix T a b l e C . Data needed t o d e s c r i b e t h e b i o l o g i c a l components

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . o f Oregon e s t u a r i e s

Page

P a r t I - E s t u a r y and E s t u a r i n e H a b i t a t

C l a s s i f i c a t i o n

i NTRODUCT l ON

An e s t u a r y i s d e f i n e d by P r i t c h a r d (1967b) as "a semi-enclosed c o a s t a l

body o f wa te r wh ich has a f r e e connec t ion w i t h t h e open sea and w i t h i n which

sea wa te r i s measurably d i l u t e d w i t h f r e s h wa te r d e r i v e d f r o m l a n d d ra inage . "

There a r e 21 ma jo r e s t u a r i e s ( F i g . 1) a l o n g Oregon's c o a s t l i n e . T h e i r

dimensions v a r y c o n s i d e r a b l y , r a n g i n g from t h e 93,782 a c r e Columbia R i v e r e s t u a r y

( D i v i s i o n o f S t a t e Lands [DSLI 1973) a t t h e n o r t h e r n border t o t h e 130 a c r e Win-

chuck e s t u a r y (Percy e t a l . 1974) i n t h e extreme sou th . The e c o l o g i c a l charac-

t e r i s t i c s o f Oregon e s t u a r i e s a l s o v a r y s i g n i f i c a n t l y i n terms o f r i v e r f l o w ,

depth , s a l i n i t y , m i x i n g , sediment compos i t i on , and shape. Corresponding

d i f f e r e n c e s i n t h e c o m p o s i t i o n and d i s t r i b u t i o n o f t h e b i o l o g i c a l communit ies

rep resen ted i n each system a r e a l s o e v i d e n t .

Economic and s o c i a l a c t i v i t i e s a s s o c i a t e d w i t h Oregon e s t u a r i e s a r e as

v a r i e d as t h e i r p h y s i c a l and b i o l o g i c a l f e a t u r e s . A v a r i e t y o f user groups

compete f o r l i m i t e d e s t u a r i n e space f o r boat moorage, wa te r -bo rn t r a n s p o r -

t a t i o n , shore land development, waste d i s p o s a l , r e c r e a t i o n , h a r v e s t o f f i s h and

s h e l l f i s h , and s c i e n t i f i c research . The d i v i s i o n o f resources among these

d i v e r s e i n t e r e s t s r e q u i r e s d i f f i c u l t cho ices between p r e s e r v a t i o n and develop-

ment o f s p e c i f i c s i t e s w i t h i n each e s t u a r y . I n o r d e r t o make in fo rmed d e c i s i o n s ,

p lanners must c o n s i d e r t h e p h y s i c a l and b i o l o g i c a l f a c t o r s t h a t t y p i f y each

e s t u a r i n e system and t h e p o t e n t i a l e f f e c t s o f each proposed a c t i v i t y .

Resource p l a n n i n g and management dec is ion -mak ing f o r most n a t u r a l systems

a r e complex due t o t h e l a r g e number o f v a r i a b l e s t h a t i n t e r a c t and i n f l u e n c e

t h e c y c l i n g o f m a t e r i a l s , f l o w o f energy, and d i s t r i b u t i o n o f spec ies . T h i s

i s p a r t i c u l a r l y t r u e o f e s t u a r i n e systems, where d r a m a t i c env i ronmenta l changes

occur th roughou t t i d a l , d i e l , and seasonal c y c l e s . Because ecosystems a r e

complex, resource c l a s s i f i c a t i o n s have o f t e n been developed as a conven ien t

1

COLUMBIA RlVER

NECANICUM RlVER

NEHALEM RlVER

NESTUCCA BA

SALMON RIVER.

YAQUINA BAY

SIUSLAW RlVER

UMPQUA RIVER- REEDSPORT

L.----- 1 'L - - - - - - _. . _-

D O U G L A S

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!

B E A C H I

PISTOL RlVER

CHETCO R l V E R WINCHUCK RIVER

F i g . 1 . Oregon e s t u a r i e s .

2

method f o r s i m p l i f y i n g , g e n e r a l i z i n g , and c a t e g ~ r i z i ~ l g i n f o r m a t i o n . E c o l o g i -

c a l c l a s s i f i c a t i o n s h e l p t o i d e n t i f y c o n t r o l l i n g f a c t o r s i n n a t u r a l e n v i r o n -

ments. They a l s o h i g h l i g h t s i m i l a r i t i e s and d i f f e r e n c e s among b i o l o g i c a l and

p h y s i c a l resources and processes t h a t may w a r r a n t s i m i l a r o r d i s t i n c t manage-

ment s t r a t e g i e s . C l a s s i f i c a t i o n systems t h a t can be a p p l i e d t o s p e c i f i c geo-

g r a p h i c a l zones can be p a r t i c u l a r l y u s e f u l t o resource managers. Regu la to ry

boundar ies can be superimposed o v e r those n a t u r a l f e a t u r e s t h a t a r e most

i m p o r t a n t t o t h e management program.

T h i s r e p o r t desc r ibes a p h y s i c a l and b i o l o g i c a l c l a s s i f i c a t i o n system

developed t o f a c i l i t a t e resource management d e c i s i o n s and impact assessments

o f Oregon e s t u a r i e s . LCDC's E s t u a r i n e Resources Goal (LCDC 1977b) r e q u i r e s t h a t

c o a s t a l p l a n n i n g agenc ies e s t a b l i s h r e g u l a t o r y boundar ies o r management u n i t s

t o govern uses arid p r o t e c t t h e d i v e r s i t y o f Oregon e s t u a r i e s . T h i s resource

c l a s s i f i c a t i o n system i s based on many o f t h e h a b i t a t s and communit ies d i scussed

i n t h e E s t u a r i n e Resources Goal, a n d , t h e r e f o r e , has d i r e c t a p p l i c a t i o n f o r

d e s i g n a t i n g a p p r o p r i a t e management u n i t s f o r p a r t i c u l a r e s t u a r i n e l o c a t i o n s .

CRITERIA FOR ESTUARINE CLASSIFICATION

Severa l c l a s s i f i c a t i o n s have been used t o d e s c r i b e ma jo r p h y s i c a l f e a t u r e s

t y p i c a l o f e n t i r e e s t u a r i n e systems. P r i t c h a r d (1967b) i d e n t i f i e d f o u r major

c a t e g o r i e s o f e s t u a r i e s a c c o r d i n g t o t h e i r geomorphology: drowned r i v e r v a l l e y ,

f j o r d , b a r - b u i l t , and t e c t o n i c . O f t h e 21 ma jo r e s t u a r i e s i n Oregon, a l l b u t

two f a l l under t h e drowned r i v e r ca tegory . A l though drowned r i v e r e s t u a r i e s

have been f u r t h e r d e f i n e d a c c o r d i n g t o t h e i r m i x i n g c h a r a c t e r i s t i c s ( P r i t c h a r d

1967a), t h e m a j o r i t y o f Oregon e s t u a r i e s exper ience l a r g e seasonal v a r i a t i o n s

i n r i v e r f l o w t h a t can r e s u l t i n a v a r i e t y o f m i x i n g c l a s s i f i c a t i o n s .

Geographica l c l a s s i f i c a t i o n s have been used t o d i f f e r e n t i a t e e s t u a r i e s

a c c o r d i n g t o b i o l o g i c a l , g e o l o g i c a l , and c l i m a t i c c h a r a c t e r i s t i c s (Hedgpeth 1957)

~ o s t geograph ica l approaches have n o t been h e l p f u l i n i d e n t i f y i n g types o f

Oregon e s t u a r i e s because they have focused on v e r y broad r e g i o n a l d i f f e r e n c e s .

West coas t b iogeogl-aphica l p r o v i n c e s have n o t been s a t i s f a c t o r y f o r Oregon

e s t u a r i n e c l a s s i f i c a t i o n e i t h e r , s i n c e l o c a l env i ronmenta l v a r i a t i o n s i n depth,

c i r c u l a t i o n , degree o f exposure, and r i v e r f l o w a r e g e n e r a l l y more s i g n i f i c a n t

than c o a s t a l c l i m a t i c d i f f e r e n c e s , upon which b i o g e o g r a p h i c a l d i s t i n c t i o n s a r e

based.

I n 1974, d u r i n g t h e e a r l y phases o f development o f Oregon 's c o a s t a l zone,

management program, t w e l v e c a t e g o r i e s o f e s t u a r i e s were i d e n t i f i e d i n t h e

s t a t e (Tab le 1 ) a c c o r d i n g t o f o u r c r i t e r i a : geomorphology, m i x i n g c h a r a c t e r -

i s t i c s , r e l a t i v e amounts o f t i d e l a n d s and ee lg rass , and " t e r r e s t r i a l and

mar ine b i o l o g i c a l va lue" (Wi l sey and Ham 1974). The c a t e g o r i e s were used i n

a broad e v a l u a t i o n o f t h e " t o l e r a n c e o f use" o r a genera l impact a n a l y s i s f o r

I I each c l a s s o f e s t u a r y .

1 T h i s c l a s s i f i c a t i o n i s inadequate f o r s e l e c t i n g areas w i t h i n e s t u a r i e s

a p p r o p r i a t e f o r development o r p r e s e r v a t i o n f o r a v a r i e t y o f reasons. There

a r e more than h a l f as many c a t e g o r i e s as t h e r e a r e ma jo r e s t u a r i e s i n Oregon.

Thus, i t does l i t t l e t o h i g h l i g h t s i m i l a r i t i e s . Geomorphology and m i x i n g t ype

a lone p r o v i d e l i t t l e b a s i s f o r d i f f e r e n t i a t i n g Oregon e s t u a r i e s . The remain ing

fac tors- -amount o f t i d e l a n d s and e e l g r a s s and t e r r e s t r i a l and mar ine b i o l o g i c a l

v a l u e - - a r e i l l - d e f i n e d and were s u b j e c t i v e l y a p p l i e d .

Researchers have a l s o developed more d e t a i l e d c l a s s i f i c a t i o n s , b u t these

have o f t e n tended t o overemphasize s i n g l e f a c t o r s . C a r r i k e r (1367), f o r example,

d i v i d e d e s t u a r i e s g e o g r , p h i c a l l y a c c o r d i n g t o s a l i n i t y ranges and r e s u l t i n g

species d i s t r i b u t i o n s (Tab le 2 ) . However, seasonal v a r i a b i l i t y i n Oregon

e s t u a r i e s c o m p l i c a t e s s a l i n i t y p a t t e r n s , p a r t i c u l a r l y i n e s t u a r i e s hav ing l a r g e

dra inages. S a l i n i t y g r a d i e n t s i n e s t u a r i e s w i t h sma l l d ra inages a r e compressed

over r e l a t i v e l y s h o r t d i s t a n c e s and a r e n o t e a s i l y de f ined .

~ ~ b i ~ I. c l a s s i f i c a t i o n of 20 major Oregon e s t u a r i e s ( W i i i e y and Ham 1374)-

I low/iaw-moderate low-moderare/ ' ~ ~ ~ a n i c u r n R ive r law-moderate cheico R ive r

!

I

~ s f u a r i e s

E l k R ive r P i r f o l R ive r Sixes R ive r "inchuck R iver

Netar ts Bay sand Lake

lsfhmur and Davis Sloughs Shinglchouse, Caaibank, Pony and Kentuck Sioughr ( C o s Bay)

Coos B a y / C ~ s R iver

n iggr cove (Ti l lamaak Bayl ca tch ing Slough (Coos Bay) L i n t and Eckman sloughs (Alsea Bayl

I moderate lh igh 1 moderate-high/ I moderate-high

1

Percentage eelgrass/ f i d e i a n d

low/low

rodera te -h igh / moderate-high/

law/iow

i ow-moderatel iow-moderate

moiaderate/~derate

l a d h i g h

I /

!Marine b i o l o g i c a l / t e r r e s t r i a l value

moderate/low

high/moderafe-high

l o w l m d e r a f e

law-moderafe/iaw

,ow-moderate/moderate-

~ h y r i s a l type

B l i n d

B a r - b u i l t

orowned r i v e r

iaw/moderaie-high

Mix ing c h a r a c t e r i r f i s s

wel l -mixed

I i i i

moderafe/roderafe-

moderale/moderate t

L i t t l e Nerrucca

i h igh salmon River

I 1 ~ l r ~ a Bay ( i n c l u d i n g D r i f t

. : 1 I I I I

I' I !

l

Yaquina Bay s ius iaw

?he mlnoi estuaries in a r e rot me 20 estusrlss in thls report.

.- . C N m

m a) L - 0 I] m u -

b- 0

m - - - r m m m % 1 S - T

Z Z - 2 - - 5 2 E g

Perhaps one o f t h e most common approaches t o e c o l o g i c a l c l a s s i f i c a t i o n o f

mar ine and e s t u a r i n e env i ronments i s based on c h a r a c t e r i s t i c a s s o c i a t i o n s o f

b e n t h i c spec ies (Petersen 1913; Thorson 1957). I n many cases e c o l o g i s t s a l s o

have a t tempted t o c o r r e l a t e observed b e n t h i c d i s t r i b u t i o n s w i t h sediment

c h a r a c t e r i s t i c s (Sanders 1958). A l though sediment may be t h e m a j o r f a c t o r i n

r e l a t i v e l y s t a b l e mar ine communi t ies , s a l i n i t y , tempera tu re , and degree o f

exposure may prove t o be o f equal o r g r e a t e r impor tance i n d e t e r m i n i n g community

compos i t i on and d i s t r i b u t i o n , p a r t i c u l a r l y i n Oregon 's r e l a t i v e l y s m a l l ,

s h a l l o w e s t u a r i e s .

I n o r d e r t o c o n s i d e r a number o f f a c t o r s t h a t may c o n c u r r e n t l y i n f l u e n c e

community d i s t r i b u t i o n , b i o l o g i s t s have i d e n t i f i e d m a j o r geograph ic , b i o l o g i c ,

o r geomorphic f e a t u r e s t h a t appear t o r e p r e s e n t d i s t i n c t e s t u a r i n e env i ronments .

For example, R i c k e t t s and C a l v i n (1968) i d e n t i f i e d t y p i c a l spec ies a s s o c i a t e d

w i t h a number o f e c o l o g i c a l s u b d i v i s i o n s w i t h i n e s t u a r i e s such as rocky shores ,

w h a r f p i l i n g s , and sand, mud, and e e l g r a s s f l a t s . A l though t h e method a f

Odum e t a l . (1974) a l s o i n c l u d e d some h a b i t a t c a t e g o r i e s (e.g. marshes,

" temperate g rass f i a t s ) , i t d i d n o t i n c o r p o r a t e t h e f u l l range o f e s t u a r i n e

h a b i t a t t ypes and g e n e r a l l y confused e n t i r e e c o l o g i c a l systems w i t h sub-

d i v i s i o n s o f those systems.

The f o l l o w i n g c r i t e r i a were s t r e s s e d i n d e v e l o p i n g an e s t u a r i n e c l a s s i f i -

c a t i o n system f o r Oregon i n l i g h t o f p l a n n i n g and management needs and t h e

inadequac ies o f e x i s t i n g c l a s s i f i c a t i o n s :

I . The c a t e g o r i e s chosen f o r a c l a s s i f i c a t i o n system shou ld r e f l e c t

t h e p a r t i c u l a r g o a l s o f t h e management program. For example, i t i s

i m p o r t a n t t o c l a s s i f y those processes o r f e a t u r e s t h a t a r e v i t a l t o

e s t u a r i n e p r o d u c t i v i t y such as s a l t marshes, submerged grass beds,

e t c . The degree o f s p e c i f i c i t y o f t h e c l a s s i f i c a t i o n system i s a l s o

dependent upon t h e management g o a l s . Very b road management o b j e c t i v e s

may be served by a c l a s s i f i c a t i o n o f e s t u a r y t ypes , b u t d e c i s i o n s con-

c e r n i n g t h e s i t i n g o f f a c i l i t i e s w i t h i n an e s t u a r y r e q u i r e much more

d e t a i l e d h a b i t a t ana lyses .

2. The components o f t h e c l a s s i f i c a t i o n system shou ld be r e a d i l y

i d e n t i f i a b l e and measurable. F a c t o r s t h a t a r e h i g h l y v a r i a b l e season-

a l l y o r s p a t i a l l y a r e more d i f f i c u l t t o d e f i n e than those t h a t a r e

more s t a b l e .

3 . The c l a s s i f i c a t i o n shou ld be immed ia te ly u s e f u l b u t f l e x i b l e so

t h a t i t can be r e v i s e d and updated as new i n f o r m a t i o n i s a v a i l a b l e .

The USFWS developed a h a b i t a t c l a s s i f i c a t i o n system (Cowardin e t a l . 1977)

f o r e s t u a r i e s t h a t s a t i s f i e s many o f t h e above c r i t e r i a ( F i g . 2 ) . T h e i r c l a s s i f i -

c a t i o n i s h i e r a r c h i c a l , r a n g i n g f rom t h e broad c a t e g o r i e s o f s u b t i d a l and i n t e r -

t i d a l t o more s p e c i f i c c h a r a c t e r i s t i c s (e .g . sediment t y p e s ) . As a r e s u l t , i t

can be adapted t o genera l e s t u a r i n e management p o l i c i e s o r s i t e - s p e c i f i c p r o -

p o s a l s . The h i e r a r c h y can be r e a d i l y updated and more d e t a i l can be added as new

r e s o u r c e d a t a become a v a i l a b l e .

The h a b i t a t c a t e g o r i e s i n t h e USFWS c l a s s i f i c a t i o n c h a r a c t e r i z e e c o l o g i c a l

s u b u n i t s w i t h i n e s t u a r i e s t h a t c o n t r o l t h e d e n s i t y and c o m p o s i t i o n o f b i o l o g i c a l

communi t ies . The c l a s s l e v e l o f t h e h i e r a r c h y c o n s i s t s o f n a t u r a l f e a t u r e s

t h a t can be e a s i l y mapped f rom a e r i a l photos o r o b s e r v a t i o n s , w h i l e more i n -

t e n s i v e sampl ing programs may be r e q u i r e d t o de te rm ine subc lass and community-

t y p e c a t e g o r i e s . The USFWS c l a s s i f i c a t i o n a l s o l i s t s a d d i t i o n a l f a c t o r s o r

" m o d i f i e r s " o f t h e c l a s s i f i c a t i o n t o d e s c r i b e s a l i n i t y range, degree o f t i d a l

i n u n d a t i o n and exposure, and t ypes o f man-made a l t e r a t i o n s .

We have m o d i f i e d and expanded t h e USFWS c l a s s i f i c a t i o n system t o i n c l u d e

e s t u a r y and subsystem types as w e l l as h a b i t a t s . The f o l l o w i n g d i s c u s s i o n

T, m v Dead

Broad-leaved Evergreen----------Rhizophora mangle

Y

Nonpersistent-------------------Nuphar advena pers is ten t-------..........----.-- S p a r t i n a a l t e r n ~ f l o r a

Organic Mud Sand

Y Cobb idg rave i

F loa t i ng ........................ E l c h h o r n i c r a s s i p e s Float ing- leaved---- - - - - - - - - - - - - -Nymphae. odorata Submergent vascular-------------- mar l t ima Subrnergent algal------ - - - - - - - - - - -

- - Organic Mud ........-.-.---.------.....-.Macoma - Sand .........-..--.------.......Renil la - Cobble/gravei - - - - - - - - - - - - - - - - - - -Deedraster

d e s c r i b e s t h i s c l a s s i f i c a t i o n as i t a p p l i e s t o t h e v a r i o u s types o f e s t u a r i e s

i n Oregon.

PHYSICAL CLASSIFICATION OF OREGON ESTUARIES

I n d e v e l o p i n g an e s t u a r y c l a s s i f i c a t i o n system f o r Oregon, we have examined

t h e 20 l a r g e r e s t u a r i e s shown i n F i g . 1 , e x c l u d i n g t h e Columbia R i v e r e s t u a r y .

The LCDC E s t u a r i n e Resources Goal (1977b) d e f i n e s t h e upstream boundary o f these

e s t u a r i e s as t h e head o f t i d e . Many researchers emphasize t h e e x t e n t o f s a l t

wa te r i n t r u s i o n as t h e i n l a n d l i m i t o f e s t u a r i n e c o n d i t i o n s ( P r i t c h a r d 1967b).

I n a number o f Oregon 's l a r g e r drowned r i v e r e s t u a r i e s , t i d a l i n f l u e n c e c o n t i n u e s

f a r beyond t h e zone o f f r e s h and s a l t w a t e r m i x i n g , and t h e r e i s o f t e n a marked

e c o l o g i c a l t r a n s i t i o n f rom deeper t i d e w a t e r s e c t i o n s t o t h e f a s t f l o w i n g r i v e r s

and t r i b u t a r i e s t h a t r i s e i n t h e c o a s t a l mounta ins . For c o n s i s t e n c y w i t h

Oregon's p r e s e n t management program, t h e f o l l o w i n g c l a s s i f i c a t i o n i n c o r p o r a t e s

LCDC's t i d a l d e f i n i t i o n o f e s t u a r i e s .

P h y s i o g r a p h i c Prov inces

A l t h o u g h s i m i l a r c l i m a t i c c o n d i t i o n s p r e v a i l t h roughou t most o f t h e Oregon

c o a s t , two ma jo r p h y s i o g r a p h i c p r o v i n c e s d i v i d e n o r t h and sou th coas t e s t u a r i e s .

The Coast Range

A p r i m a r y f e a t u r e o f t h e c e n t r a l and n o r t h e r n c o a s t o f Oregon i s t h e

Coast Range ( F i g . 3 ) , bounded on t h e e a s t by t h e W i l l a m e t t e R i v e r , on t h e n o r t h

by t h e Columbia R i v e r , and on t h e sou th by t h e C o q u i l l e R i v e r ( ~ i c k e n 1965).

The i r r e g u l a r c o a s t l i n e i n t h i s r e g i o n c o n s i s t s o f beaches i n t e r r u p t e d by

b a s a l t i c headlands, r i v e r mouths, and s h a l l o w bays. A l though a number o f r i v e r s

descend t h e wes te rn s lopes w i t h i n a s h o r t d i s t a n c e o f t h e W i l l a m e t t e V a l l e y , o n l y

t h e Umpqua c rosses t h e e n t i r e p r o v i n c e .

Geo log ic f e a t u r e s o f t h e Coast Range i n f l u e n c e t h e p h y s i c a l and b i o l o g i c a l

10

YAQUI"" ' " w b ~ ~ ~ o ~ ~ ( ' C O R V I I L L I S

ALSEA BAY-

UMPOUA RlVER R E E D S P O R T

COOS BA

COQUI LLE RlVER -- A a SIXES RlVER

a ELK

MOUNTAINS

ROGUE RIVER-- GRANTS P A 5 5

B E A C H

PISTOL RIVER

B R O O K I N G 5

CHETCO R I V E R ---- WINCHUCK RIVER----

\ F i g . 3 . The Coast Range a n d K l a m a t h Mountain physiographic provinces o f the Oregon Coast. a The headwaters o f the ~ l k and Slxes drainages are i n t h e Klamath Mountaln

provlnce although the mouths o f these r l v e r s are wlthln the Coast 1i;lnge province (Uicken 1 9 6 5 ) .

1 1

c h a r a c t e r i s t i c s o f t h e n o r t h e r n Oregon e s t u a r i e s and d i s t i n g u i s h them f rom those

t o t h e south . Predominant f o r m a t i o n s i n c l u d e sandstone, sha les , and i n t r u s i o n s

o f igneous r o c k (Dicken 1965). N o r t h c o a s t a l s o i l s i n t h i s r e g i o n a r e much l e s s

s t a b l e . As a r e s u l t , ample m a t e r i a l has been a v a i l a b l e t o b u i l d dunes, p a r t i c u -

l a r l y between Coos Bay and t h e Columbia R i v e r . The dunes have had a m a j o r impact

on t h e n o r t h coas t , changing r i v e r courses and b l o c k i n g s m a l l e r d ra inages t o fo rm

c o a s t a l l akes . E x t e n s i v e d e p o s i t s o f f i n e Coast Range sed iments , wh ich have

c r e a t e d p r o d u c t i v e i n t e r t i d a l h a b i t a t s , occur i n numerous n o r t h coas t e s t u a r i e s . ,

The Klamath Mounta ins

South o f t h e Coqui l l e R i v e r and e a s t o f t h e Cascade l a v a p l a t e a u ( ~ i g . 3) ,

t h e iand i s h i g h l y d i s s e c t e d , and t h e rock f o r m a t i o n s a r e r e l a t i v e l y o l d and

metamorphosed (Smi th 1940). F o l d i n g and f a u l t i n g i s r e l a t i v e l y more complex,

topography i s g e n e r a l l y s t e e p e r , and t h e rock i s more r e s i s t a n t t o e r o s i o n than

i n t h e Coast Range (Dicken 1965). Consequent ly, t h e sediment load o f e s t u a r i n e

t r i b u t a r i e s i s low, and t h e broad p r o d u c t i v e t i d a l f l a t s and marshes a s s o c i a t e d

w i t h t h e l a r g e r , s h a l l o w embayments o f t h e n o r t h coas t a r e l e s s c h a r a c t e r i s t i c o f

e s t u a r i e s i n t h e Klamath Mounta in p r o v i n c e . The s teep s lopes r e s t r i c t t h e land-

ward e x t e n t o f t h e t i d e and, hence, t h e s i z e o f e s t u a r i e s l o c a t e d i n t h e r e g i o n .

T i d a l i n f l u e n c e on t h e Rogue R i v e r , t h e l a r g e s t d ra inage on t h e s o u t h coas t

2 (5100 m i ) and t h e o n l y r i v e r t o t r a v e r s e t h e e n t i r e Klamath r e g i o n , extends

o n l y about 4.5 m i l e s f rom t h e e s t u a r y mouth.

Geomorphology

W i t h i n t h e two major p h y s i o g r a p h i c p rov inces o f t h e Oregon c o a s t , s e v e r a l

c lasses o f e s t u a r i e s have a l r e a d y been i d e n t i f i e d a c c o r d i n g t o t h e i r geomorphology

1sey and Ham 1974). T h i s c l a s s i f i c a t i o n d i s t i n g u i s h e s t h r e e p r i m a r y types

a r i e s (Table 1 ) .

Drowned r i v e r v a l l e y e s t u a r i e s

Host o f Oregon's e s t u a r i e s a r e drowned r i v e r v a l l e y s , formed as t h e lower

p o r t i o n s o f r i v e r s were inundated by a r i s e i n sea l e v e l . Along t h e East

Coast o f t h e U n i t e d S t a t e s , such e s t u a r i e s a r e o f t e n a s s o c i a t e d w i t h broad

c o a s t a l p l a i n s ( P r i t c h a r d 1967b). However, t h e c o a s t a l p l a i n i n Oregon i s

narrow, and t h e e s t u a r i e s a r e r e l a t i v e l y s m a l l . I n t h e drowned r i v e r e s t u a r i e s

o f t h e Coast Range w i t h low g r a d i e n t s , t i d e w a t e r o f t e n extends beyond t h e

maximum e x t e n t o f s a l t w a t e r i n t r u s i o n . On t h e C o q u i l l e , f o r example, t i d a l

i n f l u e n c e extends 41 m i l e s t o M y r t l e P o i n t , a l t h o u g h s a l i n i t y o n l y extends t o

a p p r o x i m a t e l y R i v e r M i l e 26.

B l i n d estil*

B l i n d e s t u a r i e s a r e a s p e c i a l t y p e o f drowned r i v e r v a l l e y where r i v e r

f l o w s a r e v e r y i,d d u r i n g t h e summer and o f t e n i n s u f f i c i e n t t o m a i n t a i n t h e

opening a t t h e e s t u a r y mouth (Wi lsey and Ham 1974) . The t i d e and waves f rom

t h e ocean b u i l d a ba r across t h e niouth t h a t may t e m p o r a r i l y c l o s e t h e e s t u a r y

o r fo rm a s i l l t h a t r e t a r d s t i d a l m i x i n g o f mar ine and r i v e r wa te rs . i n t h e

P i s t o l R i v e r e s t u a r y , mass m o r t a l i t i e s o f mar ine organisms i n t h e e s t u a r y have

been documented ( c I i f t o n e t a l . 1973) when s a l i n i t i e s dropped f o l l ow ing long

p e r i o d s o f f r e s h wa te r ponding beh ind t h e bar .

Bar-bu i l t E s t u a r i e s

B a r - b u i l t e s t u a r i e s a r e formed by t h e b u i l d u p o f s p i t s o r b a r r i e r beaches

between headlands. The b a r r i e r beach may be broken by i n l e t s ( u n l i k e b l i n d

e s t u a r i e s ) , which remain open due t o t i d a l a c t i o n r a t h e r than r i v e r f l o w

(Wi lsey and Ham 1974). B a r - b u i l t e s t u a r i e s a r e o f t e n f e d by severa l smal l

d ra inages , and t h e t o t a l f r e s h w a t e r i n p u t i s s m a l l . They a r e f r e q u e n t l y

e l o n g a t e and p a r a l l e l t h e c o a s t l i n e ( P r i t c h a r d 1967b), as e x e m p l i f i e d by

N e t a r t s and Sand Lake, t h e o n l y two b a r - b u i l t z s t u a r i e s i n Oregon.

Drainage Area v s . E s t u a r i n e Sur face Area

By d e f i n i t i o n e s t u a r i e s a r e t r a n s i t i o n s between mar ine and f r e s h w a t e r

env i ronments and, as such, c o n t a i n b o t h s i m i l a r and d i s t i n c t f e a t u r e s . B i o -

l o g i c a l and p h y s i c a l c h a r a c t e r i s t i c s w i t h i n e s t u a r i e s a r e l a r g e l y i n f l u e n c e d

by t h e r e l a t i v e c o n t r i b u t i o n o f each o f these env i ronments . There fo re , i t i s

u s e f u l t o f u r t h e r c l a s s i f y Oregon e s t u a r i e s a c c o r d i n g t o t h e s i z e o f t h e

d ra inage a rea f e e d i n g each system and t h e t o t a l a r e a i n f l u e n c e d by t h e t i d e .

F i g u r e 4 i l l u s t r a t e s a cont inuum o f Oregon e s t u a r i e s rang ing f rom r e l a t i v e l y

smal l e s t u a r i e s w i t h smal l d ra inages t o l a r g e r systems w i t h l a r g e dra inages.

E s t u a r i n e m i x i n g c h a r a c t e r i s t i c s ( m i x i n g o f s a l t and f r e s h w a t e r ) r e f l e c t

t h e ba lance between t i d a l and r i v e r f o r c e s . I n systems where t h e r a t i o o f

r i v e r f l o w t o t i d a l f l o w i s v e r y h i g h s e a s o n a l l y o r th roughou t t h e year , s t r a t i -

f i c a t i o n g e n e r a l l y occurs . T h i s i s t y p i c a l o f many o f t h e drowned r i v e r

e s t u a r i e s on l a r g e r d ra inages o f t h e n o r t h c o a s t . Mar ine dominated systems i n

Oregon c h a r a c t e r i z e d by r e l a t i v e l y low r i v e r f l o w s a r e g e n e r a l l y c o m p l e t e l y

o r p a r t i a l l y mixed due t o t i d a l and, i n some cases, w ind energ ies . The s m a l l e r

b a r - b u i l t e s t u a r i e s a r e examples o f mar ine dominated systems.

R i v e r dominated e s t u a r i e s may approach f r e s h c o n d i t i o n s v e r y near t h e

mouth, p a r t i c u l a r l y d u r i n g seasona l l y h i g h f l o w s . I n mar ine dominated

e s t u a r i e s n o t o n l y a r e s a l i n i t i e s g e n e r a l l y h i g h e r f u r t h e r up t h e e s t u a r y , b u t

seasonal v a r i a t i o n s r e l a t e d t o f l o w c o n d i t i o n s a r e l i k e l y t o be much l e s s

severe. A l though l o c a l g e o l o g i c a l c h a r a c t e r i s t i c s u l t i m a t e l y de te rm ine t h e

compos i t i on o f e s t u a r i n e d e p o s i t s , t h e d i s t r i b u t i o n and p a r t i c l e s i z e o f

sediments d e p o s i t e d i n t h e e s t u a r y w i l l va ry w i t h r i v e r and t i d a l c u r r e n t s . For

example, f i n e t e r r e s t r i a l m a t e r i a l s t r a n s p o r t e d downstream may n o t be d e p o s i t e d

d u r i n g h i g h f l o w s i n r i v e r dominated systems. On t h e o t h e r hand, s h a l l o w

p r o t e c t e d s loughs and embayments may se rve as s e t t l i n g b a s i n s f o r r i v e r - b o r n

S i T t s and c l a y s . The sediment d i s t r i b u t i o n i n Yaquina Bay ( F i g . 5 ) i l l u s t r a t e s

14

t h e i n f l u e n c e o f t i d a l and r i v e r f lows on t h e d e p o s i t i o n o f mar ine and r ,

sediments i n an e s t u a r y .

Species compos i t i on and d i s t r i b u t i o n a l s o d i r e c t l y and i n d i r e c t l y r e f l e c t

t h e r e l a t i o n s h i p between t i d a l and r i v e r f o r c e s i n Oregon e s t u a r i e s . V a r i a t i o n s

i n sediment d i s t r i b u t i o n a r e i m p o r t a n t i n d e t e r m i n i n g t h e compos i t i on and d i s -

t r i b u t i o n o f b e n t h i c fauna l communit ies. B e n t h i c f l o r a l communites a r e a l s o

a f f e c t e d by f a c t o r s such as c u r r e n t , s a l i n i t y , sediment t ype , and morphology

o f t h e e s t u a r y bas in . Major s a l t marsh o r e e l g r a s s assemblages occur i n l a r g e r

bays i n broad v a l l e y s o r f l a t s and i n s loughs. These c o n d i t i o n s a r e n o t

common i n r i v e r - d o m i n a t e d e s t u a r i e s , where t h e s h o r e l i n e i s s t r a i g h t and

s t e e p l y s loped and f reshwate r f l o w s predominate .

The p h y s i c a l and b i o l o g i c a l v a r i a t i o n s r e s u l t i n g f rom t h e a s s o r t e d s i z e s

o f Oregon e s t u a r i e s and t h e i r d ra inages a r e complex. F i g u r e 6 o u t l i n e s a

c l a s s i f i c a t i o n o f these e s t u a r i e s . I n t h e Klamath Mounta in r e g i o n t h e s l o p e

o f d r a i n a g e i s s teep, and even e s t u a r i e s on l a r g e r r i v e r s a r e ve ry s m a l l . I n

t h e Coast Range where r i v e r g r a d i e n t s a r e g e n e r a l l y l e s s severe, t h e range o f

e s t u a r y s i z e s i s more d i r e c t l y r e l a t e d t o t h e s i z e o f each d ra inage . The

c l a s s i f i c a t i o n groups e s t u a r i e s a c c o r d i n g t o m a j o r p h y s i c a l f e a t u r e s which

i n f l u e n c e b i o l o g i c a l communit ies.

OREGON ESTUARINE SUBSYSTEMS

The i n f l u e n c e o f g e o l o g i c , r i v e r i n e , and t i d a l f o r c e s on t h e compos i t i on

and d i s t r i b u t i o n o f m a t e r i a l s and spec ies makes i t p o s s i b l e t o i d e n t i f y

c h a r a c t e r i s t i c sub-environments o r subsystems w i t h i n Oregon e s t u a r i e s . The

presence and s i z e o f a p a r t i c u l a r subsystem i n a g i v e n e s t u a r y i s a r e f l e c t i o n

o f t h e r e l a t i v e i n f l u e n c e o f these f a c t o r s . A l though e x a c t boundar ies cannot

be drawn due t o t h e dynamic n a t u r e o f e s t u a r i e s , i t i s p o s s i b l e t o b r o a d l y

d e f i n e f o u r p r i n c i p a l types o f subsystems t h a t o c c u r i n Oregon e s t u a r i e s :

17

u > m .- a, m c g L a , a - m !-

m O a,

m I a, L m u a m 2- 0 c L m I E .- .- o c m al * > .- 3 U

2- 0 m u "l

.c I O al L m 2- LL LL a a w m

marine, bay, s lough, r i v e r i n e ( F i g . 7 ) .

Mar ine Subsystem

The mar ine subsystem i s a l o c a l i z e d a rea near t h e e s t u a r y mouth. I t i s

a h i g h energy zone s u b j e c t t o f r e q u e n t o r c o n s t a n t wave and t i d a l surges.

S a l i n i t i e s a r e g e n e r a l l y h igh , a l t h o u g h on l a r g e r i v e r systems va lues may be i

l ower , p a r t i c u l a r l y a t low t i d e and d u r i n g heavy w i n t e r f l o w s . Sediments a r e

g e n e r a l l y coarse, c l e a n sands o f mar ine o r i g i n . Rocky s u b s t r a t e s a r e a l s o 1 common, and i n l a r g e r e s t u a r i e s , rock j e t t i e s have been c o n s t r u c t e d t o i s t a b i l i z e t h e e s t u a r y mouth and ensure a n a v i g a b l e e n t r a n c e . U s u a l l y o n l y a

smal l percentage o f t h e mar ine subsystem i s i n t e r t i d a l .

B f ~ t h i c i n v e r t e b r a t e s i n t h i s zone may i n c l u d e spec ies found a l o n g t h e

o u t e r c o a s t as w e l l as those t h a t r e q u i r e t h e s l i g h t l y more p r o t e c t e d e n v i r o n -

ment found w i t h i n t h e e s t u a r y mouth. T u r b u l e n t c o n d i t i o n s i n t h e mar ine sub-

system o f t e n r e q u i r e p l a n t s and an ima ls t o have s p e c i a l i z e d adap ta tygns f o r

a t t a c h i n g themselves t o hard, wave-bat tered s u b s t r a t e s o r f o r r a p i d bu r row ing i n

s h i f t i n g sand. Ke lp and o r h e r l a r g e a l g a l spec ies may be found on rocky

s u b s t r a t e s , b u t u n c o n s o l i d a t e d sediments a r e g e n e r a l l y d e v o i d o f l a r g e r p l a n t s .

Most f i s h e s u t i l i z i n g Oregon e s t u a r i e s a r e mar ine spec ies . T h i s subsystem

o f t e n harbors t h e most d i v e r s e assemblage o f f i s h e s i n t h e e s t u a r y .

Due t o i t s p r o x i m i t y t o t h e mouth and i t s r e l a t i v e l y deep c o n d i t i o n s

compared t o l o c a t i o n s f u r t h e r up t h e e s t u a r y , t h e mar ine subsystem i s o f t e n

a p r e f e r r e d s i t e f o r boat bas ins and mar inas. Commercial and i n d u s t r i a l

development i s a l s o common where c o a s t a l towns a r e l o c a t e d a d j a c e n t t o t h e

e s t u a r y . A l though f l u s h i n g i s u s u a l l y r a p i d i n t h i s subsystem, crowded mar inas ,

where sewage, f i s h wastes, and p e t r o l e u m r e s i d u e s may c o n c e n t r a t e , and boat

bas ins w i t h c o n s t r i c t e d en t rances t h a t reduce t i d a l exchange p o t e n t i a l l y

t h r e a t e n w a t e r q u a l i t y . Dredging o f boa t b a s i n s and s h i p channels commonly

a l t e r s b e n t h i c h a b i t a t s i n t h e mar ine subsystems o f many Oregon est

The t o t a l impacts o f these v a r i o u s d i s t u r b a n c e s a r e n o t e a s i l y p r e d i c t e d .

Bay Subsystem

The bay subsystem i s a t r a n s i t i o n zone between mar ine and f r e s h water.

I n many e s t u a r i e s i t i s c h a r a c t e r i z e d by a broad embayment between t h e con-

s t r i c t e d e s t u a r y mouth and n a r r o w , u p r i v e r t i d e w a t e r s e c t o r s . I n some cases

t h e bay subsystem may be l e s s conspicuous b u t i d e n t i f i a b l e by a r e l a t i v e l y

l a r g e percentage o f i n t e r t i d a l land. S a l i n i t i e s i n t h i s r e g i o n may be q u i t e

v a r i a b l e due t o seasonal changes i n r i v e r f l o w , a l t h o u g h moderate t o h i g h

s a l i n i t y ranges a r e usua l . As an i n t e r m e d i a t e env i ronment , sediment types i n 'I

I t h e bay subsystem range f r o m coarse mar ine sands t o f i n e r i v e r i n e m a t e r i a l s i ( F i g . 5 ) . Bay subsystems a r e b e s t rep resen ted by e s t u a r i e s i n t h e Coast I Range p r o v i n c e , where s o f t p a r e n t m a t e r i a l s have eroded and been d e p o s i t e d t o

c r e a t e broad i n t e r t i d a l f l a t s .

The bay subsystem i s a r e l a t i v e l y p r o t e c t e d env i ronment , i s o l a t e d f rom

t u r b u l e n c e near t h e mouth and s t r o n g c u r r e n t s d u r i n g peak f l o w s i n t h e r i v e r i n e

p o r t i o n o f t h e e s t u a r y . The m i x t u r e o f mar ine and r i v e r i n e sediments and a

v a r i e t y o f v e g e t a t i o n t ypes p r o v i d e a d i v e r s i t y o f h a b i t a t s f o r b e n t h i c spec ies .

I n many Oregon e s t u a r i e s ma jo r c lam and shr imp beds t y p i c a l l y occur i n p r o -

d u c t i v e i n t e r t i d a l f l a t s o f t h e bay env i ronment . E x t e n s i v e marsh and e e l g r a s s

h a b i t a t s a r e a l s o common i n t h e l a r g e r Coast Range e s t u a r i e s .

Development i n t h e bay subsystem i s v a r i e d . P e r i o d i c d r e d g i n g i n l a r g e r

e s t u a r i e s has been necessary t o m a i n t a i n s h i p channe ls . I n some areas dredged

m a t e r i a l s have been dumped i n t h e bay, smother ing b e n t h i c organisms. Marshes

and f l a t s have been f i l l e d t o p r o v i d e more a rea f o r development. As i n t h e

mar ine subsystem, commercial and i n d u s t r i a l f a c i l i t i e s a r e common a long t h e

bay s h o r e l i n e o f many e s t u a r i e s and i n t h e p a s t have c o n t r i b u t e d p o l l u t a n t s f rom

2 1

r u n o f f o r d i r e c t d i s c h a r g e . Because t h e bay subsystem i s u s u a l l y an a rea o f

v e r y h i g h b i o l o g i c a l p r o d u c t i v i t y , i t i s a l s o a f a v o r i t e s i t e f o r b i r d watch ing,

clamming, and occas iona l c r a b b i n g and f i s h i n g .

Slough Subsystem

I s o l a t e d arms o r s loughs have o f t e n formed i n m inor d ra inages e n t e r i n g

t h e bay and m a r i n e subsystems o f many l a r g e r e s t u a r i e s . S a l i n i t y and o t h e r

c h a r a c t e r i s t i c s o f a s lough subsystem w i l l v a r y w i t h i t s l o c a t i o n r e l a t i v e t o

t h e e s t u a r y mouth and t h e volume o f f r e s h h a t e r e n t e r i n g i t s upper reaches.

Sloughs a r e u s u a l l y s h e l t e r e d env i ronments w i t h f i n e o r g a n i c sed iments , excep t

where t i d a l c u r r e n t s sweep th rough narrow channels . O f t e n s loughs a r e

s h a l l o w w i t h a h i g h percen tage o f i n t e r t i d a l land.

La rger s lough subsystems may be a microcosm o f t h e e n t i r e e s t u a r y and,

l i k e t h e bay subsystem, encompass a v a r i e t y o f i n t e r t i d a l and s u b t i d a l h a b i t a t

t ypes . P r o d u c t i v e marshes, e e l g r a s s , and m u d f l a t communit ies a r e common. I n

many areas s loughs and marsh channels p r o v i d e p r o t e c t e d r e a r i n g s i t e s f o r

j u v e n i l e f i s h e s and c rabs as w e l l as p r i m e r e s t i n g and f e e d i n g s i t e s f o r

w a t e r f o w l .

I n Oregon many marshes b o r d e r i n g s loughs have been d i k e d f o r a g r i c u l t u r a l

uses, r e s t r i c t i n g t i d a l f l u s h i n g and t h e f l o w o f n u t r i e n t - r i c h o r g a n i c m a t e r i a l

i n t o t h e e s t u a r i n e system. R e s i d e n t i a l and commercial development i s a l s o

common a l o n g some s loughs . Isthmus Slough i n Coos Bay p r o v i d e s an example o f

I i n d u s t r i a l development i n a s lough subsystem. M i l l s a l o n g t h e banks have used

t h e a rea f o r l o g s to rage , wh ich has reduced d i s s o l v e d oxygen l e v e l s and degraded

wa te r q u a l i t y . P o l l u t a n t d i scharges and s e p t i c t a n k f a i l u r e s may a l s o t h r e a t e n

wa te r q u a l i t y i n s lough subsystems where f reshwate r i n p u t i s n e g l i g i b l e and

f l u s h i n g i s o f t e n poor .

es t h e upper t i d e w a t e r p o r t i o n s o f t h e l a r g e r

Much o f t h e subsystem i s s u b t i d a l a long

n i t i e s a r e low most o f t h e year , and s t r e t c h e s

ra inages . Large seasonal v a r i a t i o n s i n r i v e r

t h i s p o r t i o n o f t h e e s t u a r y . Dur ing low

long i n upper r i v e r i n e l o c a t i o n s . Dur ing peak

h i g h t u r b i d i t y a r e common and may impact

t h e borders o f t h e r i v e r i n e subsystem,

shrub wet lands beyond s a l t w a t e r i n f l u e n c e .

d i k e s p r o t e c t s t h e s h o r e l i n e and p r o v i d e s

i n t h e s h a l l o w areas. The r i v e r t r a n s p o r t s

om these and o t h e r t e r r e s t r i a l sources t h a t may

be i m p o r t a n t t o v i t y o f t h e e s t u a r y .

se rve as r e a r i n g and h o l d i n g areas f o r

j uuen i l e anadro f r e s h w a t e r f i s h e s . They a r e a l s o c o r r i d o r s f o r

a d u l t salmonids d u r i n g spawning m i g r a t i o n s and a r e h e a v i l y f i s h e d by sportsmen.

A d u l t s t r i p e d bass and shad congregate and spawn i n t h e upper t i d e w a t e r o f

severa l l a r g e r e s t u a r i e s (e.g. Coos, Umpqua, ~ o ~ u i l l e ) . - A number o f a c t i v i t i e s f r e q u e n t l y a s s o c i a t e d w i t h t h e r i v e r i n e sybsystems

have a l t e r e d Oregon e s t u a r i e s . The c o n s t r u c t i o n o f d i k e s and bulkheads, w i t h -

drawal o f wa te r f o r i r r i g a t i o n , and t h e i n t r o d u c t i o n o f non-po in t p o l l u t a n t s

n t , and l i v e s t o c k wastes) a s s o c i a t e d w i t h

and w i l d l i f e h a b i t a t , e s t u a r i n e h y d r o l o g y ,

f e s t u a r i e s , huge expanses o f s a l t and f r e s h -

a t e pas tu re . R i p r a p and bulkheads p laced

A narrow f r i n g i n g marsh dominated by Carex l y n g b y e i f o l l o w s t h e s h o r e l i n e o f t h i s r i v e r i n e subsystem. F r i n g i n g marshes b i n d sediments, p r e v e n t s t reams ide e r o s i o n , and p r o v i d e s h a l l o w w a t e r h a b i t a t f o r f i s h and w a t e r f o w l i n t h e upper e s t u a r y . ( P . Howel 1)

a long t h e r i v e r i n e shore t o p r o t e c t r e s i d e n t i a l homes and p r o p e r t y f r e q u e n t l y

cause e r o s i o n a l o n g o t h e r s t r e t c h e s o f t h e r i v e r . P o l l u t a n t s in tkoduced i n

t h i s s e c t i o n o f t h e e s t u a r y d u r i n g s e a s o n a l l y low f l o w s may remain f o r l ong

p e r i o d s due t o t h e s low r a t e o f f l u s h i n g .

OREGON ESTUARINE HABITAT CLASSIFICATION SYSTEM

W i t h i n Oregon e s t u a r i e s and t h e i r component subsystems a number o f en-

v i ronmenta l f a c t o r s i n f l u e n c e t h e compos i t i on , d i s t r i b u t i o n , and p r o d u c t i o n o f

b i o l o g i c a l communit ies. The env i ronment occup ied by a spec ies o f t e n v a r i e s

c o n s i d e r a b l y w i t h i t s l i f e c y c l e and a c t i v i t i e s . For example, t h e r e a r e o f t e n

d i s t i n c t l o c a t i o n s f o r f e e d i n g , r e s t i n g , r e a r i n g , and spawning f o r a s i n g l e

spec ies , each c h a r a c t e r i z e d by a un ique s e t o f env i ronmenta l c o n d i t i o n s .

D e s p i t e changes t h r o u g h t i m e i n t h e e c o l o g i c a l requ i rements o f each organ ism

and t h e b i o l o g i c a l and p h y s i c a l c h a r a c t e r i s t i c s o f each e s t u a r y , i t i s p o s s i b l e

t o i d e n t i f y un ique env i ronments w i t h i n a system o r subsystem t h a t tend t o 1 I

c o n t r o l t h e p r o d u c t i o n and compos i t i on o f t h e communit ies t h a t u t i l i z e them.

For purposes o f c l a s s i f i c a t i o n and e s t u a r y management we w i l l r e f e r t o these

en t i ronments as h a b i t a t s . F i g . 8 i l l u s t r a t e s a v a r i e t y o f t y p i c a l h a b i t a t

types and a s s o c i a t e d communit ies i n a c r o s s s e c t i o n o f t h e S i l e t z e s t u a r y .

C l a s s i f i c a t i o n o f h a b i t a t s and t h e i r communit ies i s u s e f u l i n c o n s i d e r i n g

s i t e - s p e c i f i c p r o p o s a l s and e v a l u a t i n g p o t e n t i a l env i ronmenta l impacts i n

e s t u a r i e s . F i g . 9 o u t l i n e s an e s t u a r i n e h a b i t a t c l a s s i f i c a t i o n system f o r

Oregon i n c o r p o r a t i n g t i d a l regime, l a n d form, and sediment o r v e g e t a t i o n t y p e

as p r i m a r y f a c t o r s c o n t r o l l i n g b i o l o g i c a l communit ies. Obv ious ly , a c l a s s i f i -

c a t i o n o f b e n t h i c s u b s t r a t e s does n o t address a l l types o f communit ies i n

I t u a r i e s , b u t s e s s i l e p l a n t s and i n v e r t e b r a t e s a r e d i r e c t l y i n f l u e n c e d by

t t o m types, and a d a p t a t i o n s f o r bur rowing, a t tachment , and f e e d i n g a r e I

o s e l y l i n k e d t o s p e c i f i c types o f s u b s t r a t e . The d i s t r i b u t i o n o f f i s h e s and I

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o t h e r m o b i l e spec ies a r e a l s o r e l a t e d t o feed ing and spawning areas and pro-

t e c t i v e cover a l o n g t h e e s t u a r y bot tom. B e n t h i c f i l t e r feed ing i n v e r t e b r a t e s

a l s o can i n f l u e n c e t h e d i s t r i b u t i o n and d e n s i t y o f p h y t o p l a n k t o n and zoo-

p l a n k t o n i n t h e wa te r column.

Sediment d i s t r i b u t i o n r e f l e c t s n o t o n l y t h e source o f p a r e n t m a t e r i a l b u t

a l s o t h e v e l o c i t y and d i r e c t i o n o f t i d a l o r r i v e r f o r c e s t r a n s p o r t i n g t h e

sediment. There fo re , h a b i t a t d i s t r i b u t i o n i s a l s o i n f l u e n c e d bv t h e

ba lance o f these f o r c e s . R i v e r dominated systems, f o r example, have a

h i g h percentage o f low s a l i n i t y s u b t i d a l h a b i t a t c o n t a i n i n g t e r r e s t r i a l

sediments. Mar ine sediments and h i g h s a l i n i t i e s a r e i n f r e q u e n t l y found i n

these systems. E s t u a r i e s w i t h l a r g e i n t e r t i d a l h a b i t a t s i n bay and s lough

subsystems and a generous m i x t u r e o f mar ine and r i v e r i n e sediments o f f e r a

g r e a t e r d i v e r s i t y o f h a b i t a t t ypes and, i n t u r n , p r o b a b l y suppor t a g r e a t e r

d i v e r s i t y o f spec ies . A l though each subsystem may have a f u l l range o f sub-

s t r a t e and v e g e t a t i o n types, Tab le 3 i l l u s t r a t e s t h e h a b i t a t t ypes most

commonly a s s o c i a t e d w i t h each o f t h e f o u r ma jo r subsystems i n Oregon e s t u a r i e s .

I t i s i m p o r t a n t t o d i s t i n g u i s h between sediment t y p e and h a b i t a t type,

s i n c e s i m i l a r c l a s s e s o f s u b s t r a t e a l o n e do n o t r e p r e s e n t s i m i l a r env i ronments .

For example, communit ies t h a t i n h a b i t s u b t i d a l sand bottoms i n t h e lower

and upper e s t u a r y may d i f f e r s i g n i f i c a n t l y due t o v a r i a t i o n s i n s a l i n i t y o r

o t h e r f a c t o r s independent o f s u b s t r a t e t ype . The use o f s a l i n i t y and t i d a l

m o d i f i e r s i n t h e USFWS (Cowardin e t a l . 1977) h a b i t a t c l a s s i f i c a t i o n system i s

one method t o d i s t i n g u i s h o t h e r w i s e s i m i l a r env i ronments . The d e s i g n a t i o n

o f h a b i t a t types by subsystem shou ld a l s o p r o v i d e adequate d i f f e r e n t i a t i o n ,

s i n c e we have d e f i n e d subsystems a c c o r d i n g t o s a l i n i t y , c u r r e n t s , and o t h e r

f a c t o r s t h a t v a r y a l o n g a g r a d i e n t f r o m lower t o upper e s t u a r y .

The c l a s s i f i c a t i o n system p resen ted here i s a conceptua l model o f

community - h a b i t a t - subsystem r e l a t i o n s h i p s i n Oregon e s t u a r i e s .

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V e r i f i c a t i o n o f these r e l a t i o n s h i p s w i l l r e q u i r e surveys o f b e n t h i c communit ies

and s u b s t r a t e s and m a y . n e c e s s i t a t e r e v i s i o n o f t h e model. The ma jo r c a t e g o r i e s

o f h a b i t a t s shown i n F i g . 9 a r e d e f i n e d i n Appendix A and d e s c r i b e d below: I

I T i d a l Regime

The t i d e i s a ma jo r l i m i t i n g f a c t o r f o r many spec ies i n e s t u a r i e s and I I

nearshore mar ine env i ronments . The c l a s s i f i c a t i o n i n F i g . 9 d i s t i n g u i s h e s

i n t e r t i d a l and s u b t i d a l h a b i t a t s , s i n c e b i o l o g i c a l communit ies may d i f f e r

s i g n i f i c a n t l y a c c o r d i n g t o t h e degree o f t i d a l i n f l u e n c e . Spec ia l a d a p t a t i o n s

a r e r e q u i r e d by i n t e r t i d a l spec ies t o r e s i s t d e s s i c a t i o n and t o l e r a ~ e l a r g e

I v a r i a t i o n s i n tempera tu re and s a l i n i t y t h a t may be a s s o c i a t e d w i t h t i d a l

exposure.

W i t h i n i n t e r t i d a l areas, a marked z o n a t i o n o f spec ies i s o f t e n apparent

due t o v a r i a t i o n i n t h e f requency and d u r a t i o n o f exposure between lower and

upper i n t e r t i d a l e l e v a t i o n s . The USFWS c l a s s i f i c a t i o n (Cowardin e t 31 . 1977)

inc ludes m o d i f i e r s f o r i r r e g u l a r l y exposed, r e g u l a r l y f l o o d e d , and i r r e g u l a r l y

f l ooded i n t e r t i d a l a reas . These m o d i f i e r s a r e a p p r o p r i a t e t o f u r t h e r d i f f e r e n -

t i a t e i n t e r t i d a l h a b i t a t s represented i n Oregon e s t u a r i e s . However, i n t e r t i d a l

e l e v a t i o n s a r e n o t p r e s e n t l y mapped f o r any Oregon e s t u a r i e s .

I H a b i t a t Classes

Unconso l ida ted bot tom

P h y s i o l o g i c a l and morpho log ica l a d a p t a t i o n s o f b e n t h i c organisms a l l o w

c e r t a i n spec ies t o f l o u r i s h i n p a r t i c u l a r types o f sediment. The h a b i t a t

c l a s s i f i c a t i o n system ( F i g . 9) i d e n t i f i e s a range o f sediment s i z e s t h a t

rep resen t un ique env i ronments o f p a r t i c u l a r b e n t h i c spec ies . For example,

feed ing a d a p t a t i o n s o f i n v e r t e b r a t e s a r e r e l a t e d t o sediment s i z e . Coarse,

c l e a n sands a r e g e n e r a l l y i n h a b i t a t e d by organisms t h a t f i l t e r food f rom t h e

wate r column. I n q u i e t wa te rs where f i n e , o r g a n i c a l l y r i c h muds occur , d e p o s i t

feed ing po lychae tes o r o t h e r i n v e r t e b r a t e s i n g e s t t h e sediment d i r e c t l y . The

u n c o n s o l i d a t e d bot tom c l a s s o n l y a p p l i e s t o s u b t i d a l s u b s t r a t e s and communit ies.

Most i n v e r t e b r a t e s i n u n c o n s o l i d a t e d sediments l i v e w i t h i n t h e s u b s t r a t e .

Some spec ies m a i n t a i n permanent burrows, w h i l e o t h e r s l i v e on t h e s u r f a c e .

Sediment t y p e i n f l u e n c e s t h e c o n s t r u c t i o n and b u r r o w i n g methods and , the re fo re ,

t h e compos i t i on o f b e n t h i c i n v e r t e b r a t e communit ies. The impor tance o f sub-

t i d a l b e n t h i c h a b i t a t s t o f i s h e s v a r i e s w i t h t h e a v a i l a b i l i t y o f p r e f e r r e d

food i tems i n each t y p e o f s u b s t r a t e .

Because sediments l a r g e l y i n f l u e n c e t h e t y p e o f i n v e r t e b r a t e s c o l o n i z i n g

an area, a c t i v i t i e s wh ich a l t e r sediment c h a r a c t e r i s t i c s have a s i g n i f i c a n t

impact on b e n t h i c communit ies. A l though dredge o r s p o i l s i t e s can be r e c o l o n -

i zed , community s t r u c t u r e w i l l v a r y w i t h new sediment p r o p e r t i e s . A c t i v i t i e s

o r s t r u c t u r e s t h a t a l t e r e x i s t i n g c u r r e n t p a t t e r n s can have a s i m i l a r impact

on b e n t h i c communit ies i f e s t a b l i s h e d p a t t e r n s o f e r o s i o n or d e p o s i t i o n a r e

a f f e c t e d . C o n s t r u c t i o n o f j e t t i e s , d i k e s , and breakwaters and t h e d redg ing o f

n a v i g a t i o n channels can a l t e r f l o w r a t e s and p a t t e r n s , e r o d i n g o r d e p o s i t i n g

sediment. Where d e p o s i t i o n i s r a p i d , b e n t h i c communit ies may be smothered,

and where e r o s i o n i s s i g n i f i c a n t , o n l y o rg ran isms adapted t o u n s t a b l e sub-

s t r a t e s may be a b l e t o s u r v i v e . An i m p o r t a n t c o n s i d e r a t i o n i n e v a l u a t i n g

proposed development i n e s t u a r i e s i s t h e impact on c u r r e n t p a t t e r n s and s e d i -

men ta t ion processes and t h e r e s u l t i n g e f f e c t s on b e n t h i c h a b i t a t s and commun-

i t i e s .

Rock bot tom

Rock h a b i t a t s i n t h e h i g h s a l i n i t y zone near e s t u a r y mouths a r e v e r y

p r o d u c t i v e env i ronments f o r mar ine f i s h e s and i n v e r t e b r a t e s . Most s u b t i d a l

rock h a b i t a t s i n Oregon e s t u a r i e s a r e l o c a t e d near t h e mouth, where s t r o n g

I n t h e w e l l f l u s h e d env i ronment near e s t u a r y mouths, few a l t e r a t i o n s

d i r e c t l y t h r e a t e n s u b t i d a l r o c k h a b i t a t s . However, i n ca lmer wa te rs e x c e s s i v e

shading o r t u r b i d i t y may decrease p l a n t and animal p r o d u c t i o n , and r a p i d

sed imenta t ion can cover a t t a c h e d spec ies .

-.

t i d a l c u r r e n t s and t u r b u l e n c e r e q u i r e t h a t organisms be f i r m l y a t t a c h e d o r

seek t h e p r o t e c t i o n o f s h e l t e r e d c racks and c r e v i c e s . Rock o u t c r o p s a l s o

extend i n t o t h e upper e s t u a r y , p a r t i c u l a r l y i n t h e s m a l l e r systems o f t h e

Klamath r e g i o n . J e t t i e s have c r e a t e d t h e most e x t e n s i v e r o c k bot tom h a b i t a t s

i n Oregon e s t u a r i e s .

S p e c i a l i z e d and d i v e r s e fauna a r e adapted f o r a t tachment o r browsing

A q u a t i c bed ( i n t e r t i d a l and s u b t i d a l )

The a q u a t i c bed c a t e g o r i e s ( F i g . 9) r e f e r t o a l g a l and e e l g r a s s beds t h a t

f r e q u e n t l y o c c u r s u b t i d a l l y and i n t e r t i d a l l y i n bay and s lough subsystems.

I n Oregon, zostera marina i s t h e most common spec ies o f e e l g r a s s . I t can be

found growing i n sand as w e l l as mud s u b s t r a t e s . I t i s a r a p i d growing

p l a n t t h a t p r o v i d e s h a b i t a t f o r a d i v e r s e community o f e s t u a r i n e p l a n t s and

a long rock s u b s t r a t e s . Sucking dev ices , such as t h e t u b e f e e t o f s t a r f i s h , f

o r more permanent methods o f a t tachment , such as t h e b y s s u s . t h r e a d s o f

an ima ls (Thayer and P h i l l i p s 1977). I t s leaves s u p p o r t l a r g e numbers o f

a l g a l and i n v e r t e b r a t e e p i p h y t e s which a r e consumed by f i s h and l a r g e r

i n v e r t e b r a t e s . Numerous c lam spec ies a r e o f t e n a s s o c i a t e d w i t h e e l g r a s s beds.

Ee lg rass leaves a r e t h e p r i m a r y food o f b l a c k b r a n t d u r i n g t h e i r m i g r a t i o n

a long t h e Oregon c o a s t . However, most o f t h e energy i n e e l g r a s s i s u t i l i z e d

3 3

1 mussels, a r e examples o f a d a p t a t i o n s f o r rocky s u b s t r a t e s . S o f t s i l t and

! ih

! I. sandstone o u t c r o p s i n a few l o c a t i o n s p r o v i d e a un ique h a b i t a t f o r h i g h l y 1, s p e c i a l i z e d p iddock clams capab le o f b o r i n g i n t o t h e rock . A d i v e r s i t y o f

a l g a l spec ies a t t a c h t o r o c k y s u b s t r a t e s w i t h a s t r o n g basa l h o l d f a s t .

Eelgrass (zostera marina) blankets the water's surface as the rising tide in- nundates this aquatic bed in Netarts estuary. Productive eelgrass beds stabilize sediments, contribute rich organic matter at the base of estuarine food chains, and provide habitat for fish and a variety of clams and other invertebrates. (P . Howel 1 )

v i a d e t r i t a l food cha ins as dead leaves decay and n u t r i e n t s a r e re leased . I n

some e s t u a r i e s , e e l g r a s s leaves p r o v i d e a spawning s u r f a c e f o r h e r r i n g ( M i l l e r

and McRae 1978). T h i c k beds o f e e l g r a s s reduce c u r r e n t s near t h e bot tom and

promote d e p o s i t i o n o f sediment, w h i l e r o o t s and rhizomes b i n d sediments and

p r e v e n t e r o s i o n (Zieman 1977).

D i v e r s e a l g a l beds o c c u r i n Oregon e s t u a r i e s o v e r u n c o n s o l i d a t e d o r r o c k

s u b s t r a t e s , wh ich a l s o p r o v i d e a h a b i t a t f o r f i s h and i n v e r t e b r a t e s . Huge

mats o f Enteromorpha, U lva, and o t h e r a l g a l spec ies t u r n broad i n t e r t i d a l f l a t s

b r i g h t green d u r i n g s p r i n g and summer. D u r i n g l a t e f a l l and w i n t e r biomass

d e c l i n e s as t h e a l g a e decays, c o n t r i b u t i n g r i c h sources o f o r g a n i c m a t t e r and

n u t r i e n t s t o t h e system. I n some deeper, h i g h s a l i n i t y areas where t h e r e i s

s u i t a b l e s u b s t r a t e f o r a t tachment , l o n g b lades o f k e l p (e.g. N e r e o c y s t i s

l u e t k e a n a ) may be seen f l o a t i n g a t t h e w a t e r ' s s u r f a c e . Ke lp h o l d f a s t s

r e p r e s e n t a un ique m i c r o h a b i t a t f o r a r i c h community o f i n v e r t e b r a t e s (Markham

1967).

P l a n t p r o d u c t i o n i n Oregon e s t u a r i e s i s h i g h l y seasonal . The t i m i n g o f

, f i s h m i g r a t i o n s and spawning and i n v e r t e b r a t e r e p r o d u c t i o n i n e s t u a r i e s

cor responds c l o s e l y w i t h d r a m a t i c i nc reases i n p l a n t p r o d u c t i o n d u r i n g t h e

s p r i n g and summer. A l g a l and e e l g r a s s communit ies p r o b a b l y r e p r e s e n t a s i g n i -

f i c a n t p o r t i o n o f t h e p r i m a r y p r o d u c t i o n i n many Oregon e s t u a r i e s .

E s t u a r y p l a n s shou ld p r o t e c t a q u a t i c beds b o t h as a source o f o r g a n i c

m a t t e r f o r t h e e n t i r e system and as a h a b i t a t f o r f i s h and i n v e r t e b r a t e s .

Reduct ion o f l i g h t p e n e t r a t i o n due t o shading o r t u r b i d i t y can l i m i t p l a n t

growth. Logging and road c o n s t r u c t i o n i n t h e upper watershed and d redg ing

a c t i v i t i e s i n t h e e s t u a r y can i n c r e a s e t u r b i d i t y . Reduced f l u s h i n g o f e e l g r a s s

and some a l g a l communit ies may decrease n u t r i e n t and gas exchange and, as a

r e s u l t , p l a n t p r o d u c t i o n . S i g n i f i c a n t m o d i f i c a t i o n o f temperature o r s a l i n i t y

Dense mats o f green a l g a e appear a long t h e f l a t s o f many Oregon e s t u a r i e s d u r i n g t h e s p r i n g and summer, p r o v i d i n g e s t u a r i n e food cha ins w i t h ano ther i m p o r t a n t source o f o r g a n i c m a t e r i a l . A t h i c k growth o f sea l e t t u c e (Ulva l a c c t u c a ) covers t h i s cobb le /g rave l f l a t . (P. Howe l l )

3 6

p a t t e r n s f rom changes i n f r e s h w a t e r f l o w o r e s t u a r i n e c i r c u l a t i o n may f u r t h e r

t h r e a t e n a q u a t i c beds.

Shore

Shores a r e narrow, s t e e p l y s loped i n t e r t i d a l h a b i t a t s t h a t occur where

r i v e r and t i d a l c u r r e n t s a r e r e l a t i v e l y s t r o n g . Because these a r e g e n e r a l l y

h i g h energy env i ronments , rocky s u b s t r a t e s o r c o a r s e sediments o f t e n predomi-

na te . A l g a l and i n v e r t e b r a t e spec ies a r e f i r m l y a t t a c h e d t o rocky shores, b u t

waves and c u r r e n t s may l i m i t p l a n t and an imal p r o d u c t i o n on u n s t a b l e , uncon-

s o l i d a t e d shores. As i n o t h e r i n t e r t i d a l h a b i t a t s , t h e r e i s a pronounced

z o n a t i o n o f p l a n t and an imal spec ies f rom lower t o upper i n t e r t i d a l e l e v a t i o n s

w i t h g e n e r a l l y fewer spec ies i n h a b i t i n g t h e upper i n t e r t i d a l zone. I n some

e s t u a r i e s , mud and sandy shores a r e i n h a b i t e d by bur row ing o r t u b e d w e l l i n g

i n v e r t e b r a t e s , wh ich a r e food sources f o r bot tom f e e d i n g f i s h e s a t h i g h t i d e .

I n some l o c a t i o n s , i n t e r t i d a l shores s e r v e as hau l o u t areas f o r ha rbor s e a l s .

Shore h a b i t a t s a r e most d i r e c t l y impacted by development a long a d j a c e n t

up lands. Shading by docks, l o g r a f t s , and o t h e r s t r u c t u r e s can reduce p l a n t

and animal p r o d u c t i o n a l o n g e s t u a r i n e shores. Communal dock f a c i l i t i e s h e l p

p reven t t h e p r o l i f e r a t i o n o f s h o r e l i n e s t r u c t u r e s than can reduce b e n t h i c

communit ies and a l t e r f l o w p a t t e r n s i n t h e immediate v i c i n i t y . I n a few

e s t u a r i e s l o g s s t o r e d a l o n g r i v e r i n e shores ground a t low t i d e c r u s h i n g

b e n t h i c organisms and c o n t r i b u t e l a r g e q u a n t i t i e s o f decay ing b a r k d e b r i s t h a t

degrade sediment and wa te r q u a l i t y . D e s t r u c t i o n o f r i p a r i a n v e g e t a t i o n above

i n t e r t i d a l shores inc reases bank e r o s i o n and losses o f p r o p e r t y and shore

h a b i t a t . Sloped shores d i s s i p a t e c u r r e n t e n e r g i e s and t h e r e f o r e a r e more r e -

s i s t a n t t o e r o s i o n than v e r t i c a l banks. Where p o s s i b l e , v e g e t a t i o n i s

p r e f e r r e d t o r i p r a p f o r c o n t r o l l i n g e r o s i o n a l o n g e s t u a r i n e shores.

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F l a t - Broad i n t e r t i d a l f l a t s commonly occur i n s lough and bay subsystems o f

Oregon e s t u a r i e s . Large s h a l l o w f l a t s s t o r e hea t and may have an i m p o r t a n t

r o l e i n t h e temperature budget o f t h e e n t i r e e s t u a r y . They a r e g e n e r a l l y

i f i e d as i n t e r t i d a l a q u a t i c beds. Even where macrovege ta t ion i s n o t e v i d e n t ,

t h e ye l low-brown c o l o r a t i o n a t t h e s u r f a c e o f some m u d f l a t s suggests b e n t h i c

d ia toms may be a v e r y s i g n i f i c a n t source o f p r o d u c t i o n .

Cock le ( C l i n o c a r d i u m n u t a l l i i ) , gaper ( ~ r e s u s c a p a x ) , b u t t e r ( s a x i d o m a s

g i g a n t e u s ) , 1 i t t leneck ( ~ r o t o t h a c a s t a m i n e a ) , and s o f t s h e l l ( ~ ~ a a r e n a r i a )

clams and mud (upoqeb ia p u g e t t e n s i s ) and ghos t ( ~ a l l i a n a s s a c a l i f o r n i e n s i s )

shr imp a r e f r e q u e n t l y a s s o c i a t e d w i t h Oregon mud and sand f l a t s . R e c r e a t i o n a l

clamming i s popu la r i n these areas d u r i n g low t i d e s , p a r t i c u l a r l y i n t h e

s p r i n g and summer. Bottom f e e d i n g f i s h e s g raze o v e r f l a t s d u r i n g h i g h t i d e .

Great b l ue heron ( ~ r d e a h e r i o d i a s ) , g r e a t e g r e t (Casmerod ius a l b u s ) , and a

v a r i e t y o f s h o r e b i r d s feed i n t h e sha l lows as t h e t i d e recedes.

B e n t h i c organisms o f t i d e f l a t s a r e s p e c i a l l y adapted f o r p a r t i c u l a r g r a i n

s i r e s o f s e d i m e n t a n d t h e temperatures and exposure o f an i n t e r t i d a l environment.

A c t i v i t i e s wh ich a l t e r sediment c h a r a c t e r i s t i c s o r t i d a l e l e v a t i o n s can

t h e r e f o r e be expected t o i n f l u e n c e b e n t h i c communit ies. F i l l i n g and d redg ing

rep resen t t h e most obv ious t h r e a t s t o f l a t h a b i t a t s . I n t h e p a s t broad f l a t s

3 9

s h e l t e r e d f rom s t r o n g c u r r e n t s and wave a c t i o n , and t h e i r g radua l s lopes tend 1 I

t o d i s s i p a t e wave and t i d a l e n e r g i e s . As a r e s u l t , f l a t s f o r m a r e l a t i v e l y

s t a b l e env i ronment f o r c o l o n i z i n g spec ies as r e f l e c t e d i n t h e h i g h d e n s i t y

and d i v e r s i t y o f organisms t h a t g e n e r a l l y l i v e t h e r e .

I Sediments o f f l a t s v a r y f rom f i n e mud t o coarse cobb le o r g r a v e l . Sha l low

depths, maximum l i g h t , and warm temperatures o f t e n r e s u l t i n e x t e n s i v e growths

o f a l g a e d u r i n g t h e s p r i n g and summer, when many o f these f l a t s may be c l a s s -

have been f i l l e d t o ex tend t h e a rea o f l e v e l up land a v a i l a b l e f o r shore land I-- development i n e s t u a r i e s . I n a few l o c a t i o n s g round ing o f l o g s s t o r e d on

i n t e r t i d a l f l a t s and shores a t low t i d e has dec imated b e n t h i c p o p u l a t i o n s

(Zegers 1978). Accumulat ions o f b a r k and wood d e b r i s near l o g s t o r a g e s i t e s

c o n t r i b u t e leacha tes , reduce oxygen l e v e l s , w h i c h can a d v e r s e l y a f f e c t

s u b t i d a l and i n t e r t i d a l b e n t h i c communit ies. Sewage, f i s h wastes, o r

I o t h e r o r g a n i c p o l l u t a n t s d i scharged o v e r f l a t s may a l s o accumulate i n t h e

sediments and reduce oxygen l e v e l s . Large numbers o f o p p o r t u n i s t i c p o l y -

chaetes (e.g. Capitella capitata) o r o t h e r i n v e r t e b r a t e s i n d i c a t i v e o f

*degraded h a b i t a t s c o l o n j z e these a reas , and spec ies d i v e r s i t y decreases. .

I n some e s t u a r i e s l o g g i n g a c t i v i t i e s i n t h e upper watershed have t r e -

~ mendously inc reased t h e r a t e o f sed imenta t ion . T i l l a m o o k Bay i s a pr ime

I I example o f an e s t u a r y t h a t has r a p i d l y f i l l e d s i n c e t h e a r e a was f i r s t s e t t l e d . I

T h i s has g r e a t l y i nc reased t h e acreage o f f l a t s and decreased t h e a rea o f

I s u b t i d a l h a b i t a t .

Because o f t h e i r v e r y h i g h p r o d u c t i v i t y and t h e i r r o l e i n temperature

r e g u l a t i o n and n u t r i e n t c y c l i n g , e s t u a r i n e t i d e f l a t s shou ld be p r o t e c t e d i n

l o c a l comprehensive p l a n s . Dredge and f i l l ; t i d e l a n d l o g s to rage ; p o l l u t a n t s ,

such as sewage and s u l p h i t e waste l i q u o r ; and a c t i v i t i e s t h a t t h r e a t e n c i r c u -

l a t i o n and sediment c h a r a c t e r i s t i c s a r e o f p r i m a r y concern. Research i s a l s o

needed t o e v a l u a t e t h e f e a s i b i l i t y and impact o f h a b i t a t r e s t o r a t i o n i n those

few i n s t a n c e s where f i l l i n g has been e x t e n s i v e . I n a l l cases s t r i c t r e g u l a t i o n

o f a c t i v i t i e s i n upper watersheds i s i m p e r a t i v e i n m a i n t a i n i n g t h e ba lance and

d i v e r s i t y o f h a b i t a t t ypes w i t h i n Oregon e s t u a r i e s .

Beach/bar

Beach/bar h a b i t a t s a r e h i g h l y dynamic env i ronments s u b j e c t t o s t r o n g

t i d a l c u r r e n t s and wave and r i v e r energ ies . Bars occur w i t h i n e s t u a r i e s as

4 1

e l o n g a t e r i d g e s o f coarse sand, cobb le , o r g r a v e l , wh ich a r e bordered by w a t e r

on a t l e a s t two s ides . I n Oregon,bars f o r m d u r i n g summer a t t h e mouths o f

s m a l l e r b l i n d e s t u a r i e s a n d , i n some cases,prevent mar ine w a t e r f rom e n t e r i n g

t h e e s t u a r i e s . S h i f t i n g bars a l s o o c c u r near t h e mouths o f l a r g e r e s t u a r i e s

o r i n upper r i v e r i n e s e c t i o n s . Because bars c o n t i n u a l l y s h i f t w i t h t h e c u r r e n t s ,

c o l o n i z a t i o n i s l i m i t e d t o r a p i d l y bu r row ing and o p p o r t u n i s t i c spec ies , i n -

c l u d i n g m o l l u s c s , c rus taceans , and po lychae tes .

Sha l low i n t e r t i d a l b a r s may ex tend as s p i t s f r o m shores near t h e mouths o f

e s t u a r i e s . I n l a r g e r systems these may be p e r i o d i c a l l y dredged t o p r o v i d e

access and a n a v i g a b l e r o u t e f o r s h i p s pass ing t h r o u g h t h e e s t u a r y . Gravel

removal o p e r a t i o n s have o c c u r r e d on bars i n t h e r i v e r i n e s e c t i o n s o f a few

sou th coas t e s t u a r i e s . The impacts on these h a b i t a t s and t h e e s t u a r y as a whole

have n o t been s t u d i e d . A sand b a r t h a t formed near t h e e n t r a n c e o f t h e

C h a r l e s t o n boat b a s i n i n Coos Bay was c o l o n i z e d by a dense p o p u l a t i o n o f r a z o r I clams ( ~ i l i ~ u a ~atula).

T i d a l marsh

T i d a l marsh h a b i t a t s , c h a r a c t e r i z e d b y r o o t e d herbaceous o r woody hydro -

phy tes t h a t grow between lower h i g h t i d e and t h e l i n e o f non-aqua t i c v e g e t a t i o n ,

occur i n many Oregon e s t u a r i e s . These can be d i v i d e d i n t o f o u r ma jo r sub-

c l a s s e s : h i g h and low s a l t marsh i n mar ine and b r a c k i s h areas and f r e s h and

shrub marshes beyond s a l t w a t e r i n f l u e n c e . Community compos i t i on o f these

marshes v a r i e s w i t h t i d a l e l e v a t i o n and f requency o f f l o o d i n g , sediment type,

and s a l i n i t y regime.

S a l t marshes have been ranked among t h e most p r o d u c t i v e ecosystems i n t h e

w o r l d ( N i e r i n g and Warren 1977) . P l a n t p roducers i n s a l t marshes i n c l u d e n o t

o n l y marsh grasses b u t a l s o macroalgae entwined among t h e g rass stems, m i c r o -

a l g a e on t h e mud s u r f a c e , and p h y t o p l a n k t o n i n t h e w a t e r column. Organic

Wel l d e f i n e d channels d r a i n i n g h i g h marshes t r a n s p o r t n u t r i e n t s t o and f rom t h e open wa te rs o f t h e e s t u a r y and p r o v i d e h a b i t a t f o r f i s h , b r i d s , and sma l l mammals. S a l t marshes r e t a r d s h o r e l i n e e r o s i o n and p u r i f y wa te r d r a i n i n g i n t o t h e e s t u a r y by f i l t e r i n g o u t wastes and p o l l u t a n t s . ( P . Howel l )

m a t e r i a l and n u t r i e n t s s t o r e d by marsh p roducers a r e consumed d i r e c t l y o r

t r a n s f e r r e d t o o t h e r p o r t i o n s o f t h e e s t u a r y as d e t r i t u s .

Marshes a r e an i m p o r t a n t h a b i t a t f o r i n v e r t e b r a t e s , w a t e r f o w l , and sma l l

t e r r e s t r i a l mammals. A d i v e r s i t y o f i n s e c t s l i v e i n and g raze on marsh grasses.

D e t r i t u s - f e e d i n g s n a i l s , scavenging crabs, and a v a r i e t y o f amphipods and

o t h e r i n v e r t e b r a t e s seek t h e food and/or p r o t e c t i o n o f marshes. The w e l l

d e f i n e d channels o f h i g h marshes i n Oregon 's bays and s loughs a r e h e a v i l y used

by j u v e n i l e Dungeness c r a b (cancer m a g i s t e r ) and a v a r i e t y o f sma l l f i s h e s

(e.g. Gas te ros teus a c u l t e a t u s ) . I n some areas t h e y may p r o v i d e impor tan t

r e a r i n g h a b i t a t f o r j u v e n i l e ch inook salmon (Dunford 1972). Marshes a l s o p r o -

v i d e r e s t i n g and f e e d i n g areas f o r l a r g e numbers o f m i g r a t i n g w a t e r f o w l .

E s t u a r i n e marshes a r e i m p o r t a n t sediment t r a p s t h a t reduce t h e f requency

o f d r e d g i n g r e q u i r e d f o r n a v i g a t i o n ( N i e r i n g and Warren 1977). They h e l p t o

s t a b i l i z e t h e shore, d i s s i p a t e f l o o d waters,and p r o t e c t shore land p r o p e r t y

f rom storms. Marshes a l s o f i l t e r and process n i t r a t e s , phosphates, and o t h e r

wastes, thus p r o v i d i n g a p o l l u t i o n b u f f e r between a d j a c e n t up land a c t i v i t i e s

and t h e e s t u a r y .

Tremendous areas o f Oregon marsh have been d i k e d t o c r e a t e up land f o r

p a s t u r e and o t h e r uses. T h i s has g r e a t l y reduced t h e h a b i t a t and p r o d u c t i v i t y

o f t h e e s t u a r i e s . E x t e n s i v e d i k i n g o f f r e s h marshes a l o n g r i v e r i n e and o t h e r

subsystems has a l t e r e d marsh community compos i t i on , channe l i zed t h e e s t u a r i n e

wa te r course, reduced p r o d u c t i v e i n t e r t i d a l s u r f a c e a rea , and r e s t r i c t e d t h e

t r a n s p o r t o f o r g a n i c m a t e r i a l s and n u t r i e n t s t o and f r o m t h e e s t u a r y . Con-

s t r u c t i o n o f causeways and roadbeds has s i m i l a r l y r e s t r i c t e d t i d a l f l o w and

m o d i f i e d marsh communit ies. F i l l i n g f o r shore land development has s a c r i f i c e d

e expanses o f marsh i n many 3regon e s t u a r i e s . C l a r k (1977) no tes " the

r t h e degree o f shore lands development, t h e g r e a t e r i s t h e need t o p re -

c o a s t a l wet lands." I n v iew o f t h e e x t e n s i v e losses i n many o f o u r

44

-.-

s t u a r i e s , comprehensive p l a n s shou ld p r e v e n t f u r c h e r d r a i n i n g , f i l i i n g , d i k i n g ,

1

n d p o l l u t i n g o f e s t u a r i n e marshes. The e f f e c t s o f b reach ing d i k e s t o r e s t o r e

ma1 l he n a t u r a l f u n c t i o n s o f t i d a l marshes i n t h e e s t u a r y shou ld r e c e i v e a h i g h

rasses. ~ r i o r i t y f o r research i n Oregon, b o t h as a means o f h a b i t a t r e s t o r a t i o n and as

~ o t e n t i a l m i t i g a t i o n f o r e s t u a r y f i l l i n g .

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ESTUARY CLASSIFICATION AND THE LCDC ESTUARINE RESOURCES GOAL 1 The LCDC E s t u a r i n e Resources Goal (1977b) e s t a b l i s h e s i t s own t y p e o f

: l a s s i f i c a t i o n system t o g u i d e p l a n n i n g d e c i s i o n s i n Oregon e s t u a r i e s . The cen- -

t r a l concept o f t h e goa l i s d ivers i ty - -management o f e s t u a r i e s and areas w i t h i n

e s t u a r i e s so t h a t a wide range o f uses and a c t i v i t i e s can occur w i t h o u t caus ing

severe damage t o t h e e s t u a r i n e ecosystem. For p l a n n i n g purposes i t i s i m p o r t a n t

t o unders tand t h e r e l a t i o n s h i p between t h e c l a s s i f i c a t i o n o f e s t u a r i e s d e s c r i b e d

i n t h i s r e p o r t and t h e c l a s s i f i c a t i o n e s t a b l i shed by LCDC (1977a,b) .

To p r o v i d e f o r a d i v e r s i t y o f uses, t h e E s t u a r i n e Resources Goal (LCDC -

l977b) r e q u i r e s t h a t l o c a l comprehensive p l a n s c l a s s i f y each e s t u a r y I n t o

management c a t e g o r i e s and " e s t a b l i s h p o l i c i e s and use p r i o r i t i e s f o r each

management u n i t . " The goal d e s c r i b e s t h r e e t ypes o f management u n i t s - - d e v e l o p -

rnent, c o n s e r v a t i o n , and n a t u r a l - - a n d d e f ~ n e s t h e c r i t e r i a f o r t h e areas i n c l u d e d

and t h e uses t h a t w i l l be a l l o w e d f o r each o f these c a t e g o r i e s . Tab les 4 and

5 d e s c r i b e t h e purpose, areas o f concern, and p e r m i s s i b l e a c t i v i t i e s f o r each

LCDC management u n i t .

LCDC a l s o adopted an a d m i n i s t r a t i v e r u l e (1977a) c l a s s i f y i n g e s t u a r i e s

a c c o r d i n g t o " t h e most i n t e n s i v e l e v e l o f development o r a l t e r a t i o n a l l o w a b l e . "

The c l a s s i f i c a t i o n des igna tes s h a l l o w and deep d r a f t development, c o n s e r v a t i o n ,

and n a t u r a l e s t u a r i e s . Each o f these c a t e g o r i e s i n c l u d e s s p e c i f i c management

u n i t s . Development e s t u a r i e s have a l l t h r e e t ypes o f management u n i t s ; conser-

v a t i o n e s t u a r i e s have c o n s e r v a t i o n and n a t u r a l u n i t s ; and n a t u r a l e s t u a r i e s o n l y

4 5

~ ~ b l e 4. Purpose and a r e a o f concern f o r n a t u r a l , c o n s e r v a t i o n , and deve lop- ment management u n i t s i n Oregon e s t ~ a r i e s . ~

N a t u r a l Management U n i t Purpose

To a s s u r e p r o t e c t i o n o f s i g n i f i c a n t f i s h and w i l d l i f e h a b i t a t s , c o n t i n u e d b i o l o g i c a l p r o d u c t i v i t y , and s c i e n t i f i c , research, and e d u c a t i o n a l needs; To p r e s e r v e n a t u r a l resources i n r e c o g n i t i o n o f dynamic, n a t u r a l , g e o l o g i c a l , and e v o l u t i o n a r y processes.

Areas o f Concern A t a minimum, a l l ma jo r t r a c t s o f s a l t marsh, t i d e f l a t s , and seagrass and a l g a l beds.

Conserva t ion Management U n i t Purpose

For l o n g - t e r m uses o f renewable resources t h a t do n o t r e q u i r e ma jo r a l t e r a t i o n s o f t h e e s t u a r y , except f o r t h e purpose o f r e s t o r a t i o n ; To conserve n a t u r a l resources and b e n e f i t s i n c l u d i n g a reas needed f o r maintenance and enhancement o f b i o l o g i c a l p r o d u c t i v i t y , r e c r e a t i o n a l and a e s t h e t i c uses, and a q u a c u l t u r e .

Areas o f Concern T r a c t s o f s i g n i f i c a n t h a b i t a t s m a l l e r o r o f l e s s b i o l o g i c a l impor tance than N a t u r a l Management areas and o y s t e r and c lam beds. P a r t i a l l y a l t e r e d areas o r e s t u a r i n e areas a d j a c e n t t o e x i s t i n g development o f moderate i n t e n s i t y (un less o t h e r w i s e needed f o r p r e s e r v a t i o n o r development c o n s i s t e n t w i t h t h e Oreson E s t u a r y C l a s s i f i c a t i o n ) .

Development Management U n i t - Purpose

To p r o v i d e f o r n a v i g a t i o n and o t h e r i d e n t i f i e d needs f o r pub1 i c , commerc ia l , and i n d u s t r i a l water-dependent uses, c o n s i s t e n t w i t h t h e l e v e l o f development o r a l t e r a t i o n a l l o w e d by t h e Oregon E s t u a r y C l a s s i f i c a t i o n .

Areas o f Concern Deep-water a reas a d j a c e n t o r i n p r o x i m i t y t o t h e s h o r e l i n e , n a v i g a t i o n channels , s u b t i d a l areas f o r i n - w a t e r d i s p o s a l o f dredged m a t e r i a l and areas o f min imal b i o l o g i c a l s i g n i f i c a n c e needed f o r uses r e q u i r i n g a l t e r a t i o n o f t h e e s t u a r y .

a Management uni t d e s i g n a t i o n s f rom LCDC (1977b) .

T a b l e 5. P e r m i s s i b l e uses f o r n a t u r a l , c o n s e r v a t i o n , and development manage- ment u n i t s i n Oregon e s t u a r i e s . a

N a t u r a l Management U n i t

1. Undeveloped l o w - i n t e n s i t y water-dependent r e c r e a t i o n 2. Research and e d u c a t i o n a l o b s e r v a t i o n 3. N a v i g a t i o n a i d e s , such as beacons and buoys 4. P r o t e c t i o n o f h a b i t a t , n u t r i e n t , f i s h , w i l d l i f e , and a e s t h e t i c resources 5 . Pass ive r e s t o r a t i o n measures

And, where c o n s i s t e n t w i t h t h e resource c a p a b i l i t i e s o f t h e a r e a and t h e purposes o f t h i s management u n i t :

6 . A q u a c u l t u r e 7. Communication f a c i l i t i e s

I 8. A c t i v e r e s t o r a t i o n measures

Conserva t ion Management U n i t

1 . Uses a l l o w e d i n n a t u r a l management u n i t 2. A c t i v e r e s t o r a t i o n measures 3 Aqu<-cul t u r e 4. Communication f a c i l i t i e s

And, where c o n s i s t e n t w i t h t h e resource c a p a b i l i t i e s o f t h e a r e a and t h e purposes o f t h i s management u n i t :

5 . H i g h - i n t e n s i t y water-dependent r e c r e a t i o n 6. Maintenance d redg ing o f e x i s t i n g f a c i l i t i e s 7. M inor n a v i g a t i o n a l improvements 8. M i n i n g and m i n e r a l e x t r a c t i o n

p

1 . Uses a l l o w e d i n Natu-a1 and Conserva t ion Management U n i t s 2 . N a v i g a t i o n 3 . \ later-dependent commercial and i n d u s t r i a l uses

And, where c o n s i s t e n t w i t h t h e resources c a p a b i l i t i e s and purposes o f t h i s management u n i t :

4 . W a t e r - r e l a t e d and non-dependent, n o n - r e l a t e d uses n o t r e q u i r i n g f i l l 5. M i n i n g and m i n e r a l e x t r a c t i o n .

As a p p r o p r i a t e needs f o r t h e f o l l o w i n g uses a l s o s h a l l be i n c l u d e d : a. Dredge o r f i l l as a l l o w e d i n t h e LCDC Goal b . \ l a t e r t r a n s p o r t channels where d r e d g i n g may be necessary c . D isposa l o f dredged m a t e r i a l d . \,later s t o r a g e a rea where needed f o r p r o d u c t s used i n o r r e s u l t i n g f rom

i n d u s t r y , commerce, and r e c r e a t i o n e. Mar inas f . A q u a c u l t u r e g . E x t r a c t i o n o f aggregate resources h. R e s t o r a t i o n

a Permissible uses from LCDC ( 1 9 7 7 b i .

have n a t u r a l management u n i t s . T a b l e 6 d e s c r i b e s LCDC's "Oreqon Es tuary I

C l a s s i f i c a t i o n " and shows how each e s t u a r y has been c a t e g o r i z e d . I

The LCDC e s t u a r y c l a s s i f i c a t i o n i s based on e x i s t i n g development p a t t e r n s , I

r a t h e r than p h y s i c a l o r b i o l o g i c a l c h a r a c t e r i s t i c s . Development e s t u a r i e s I

have ma in ta ined j e t t i e s and channels a s s o c i a t e d w i t h s h i p o r sma l l boa t

t r a f f i c . Conservat ion e s t u a r i e s l a c k m a i n t a i n e d j e t t i e s b u t have urban

development a long a d j a c e n t shore lands. N a t u r a l e s t u a r i e s have no j e t t i e s and

no urban development. I

F i g u r e 10 shows t h e r e l a t i o n s h i p between t h e LCDC c l a s s i f i c a t i o n o f

e s t u a r i e s a c c o r d i n g t o a l l o w a b l e a c t i v i t i e s and t h e c l a s s i f i c a t i o n we have 1

p repared based on p h y s i c a l c h a r a c t e r i s t i c s . A l though t h e LCDC c l a s s i f i c a t i o n I i n c l u d e s a d i v e r s i t y o f a c t i v i t i e s among e s t u a r i e s , these uses a r e n o t d i s -

t r i b u t e d u n i f o r m l y among d i f f e r e n t e s t u a r y t ypes . For example, a l l deve lop- I

ment e s t u a r i e s a r e l a r g e drainage/drowned r i v e r systems, w h i l e n a t u r a l e s t u a r i e s ~ a r e smal l b a r - b u i l t , d r o w n e d r i v e r , o r b l i n d e s t u a r i e s w i t h smal l d ra inages .

There a r e o n l y two n a t u r a l e s t u a r i e s among t h e 14 Coast Range systems, w h i l e 1 t h r e e o f t h e s i x Klamath e s t u a r i e s a r e des igna ted as n a t u r a l . I

Development p a t t e r n s have been a ma jo r f a c t o r i n f l u e n c i n g f u t u r e manage- I ment g o a l s f o r Oregon e s t u a r i e s . However, t h e e s t u a r i e s c l a s s i f i e d f o r

development a r e o f t e n t h e most b i o l o g i c a l l y p r o d u c t i v e . Large drainage/drowned I

r i v e r systems i n t h i s c a t e g o r y a r e o f t e n c h a r a c t e r i z e d by l a r g e i n t e r t i d a l

vegetated f l a t s and a h i g h d i v e r s i t y o f spec ies and h a b i t a t t y p e s . I n o r d e r

t o p r o t e c t t h e d i v e r s i t y o f Oregon e s t u a r i e s , comprehensive p l a n s must ca re -

f u l l y p r o t e c t t h e range o f e s t u a r y types as w e l l as t h e h a b i t a t s and communit-

i e s w i t h i n them. T h i s i s e s p e c i a l l y i m p o r t a n t i n t h e l a r g e r c o n s e r v a t i o n

and development e s t u a r i e s , where t h e p o t e n t i a l f o r env i ronmenta l d e g r a d a t i o n

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The d e s i g n a t i o n o f management u n i t s as s p e c i f i e d i n t h e E s t u a r i n e

Resources Goal (LCDC 1977b) w i l l de te rm ine t h e ba lance between development

and resource p r o t e c t i o n w i t h i n each Oregon e s t u a r y . A l though t h e goa l

b r o a d l y d e f i n e s t h e purpose o f each management u n i t , t h e s i z e o f a u n i t and

i t s l o c a t i o n i n r e l a t i o n t o o t h e r management u n i t s w i l l be e s t a b l i s h e d i n

each l o c a l comprehensive p lan . Loca l comprehensive p l a n s shou ld d e s i g n a t e t h e

s i z e and l o c a t i o n o f management u n i t s t h a t w i l l i n s u r e p r o t e c t i o n o f m a j o r

e c o l o g i c a l s u b u n i t s . T h i s may cor respond t o s p e c i f i c h a b i t a t s , groups o f

h a b i t a t s , o r e n t i r e subsystems. The c l a s s i f i c a t i o n o f e s t u a r i n e subsystems

and h a b i t a t s ( F i g . 9 ) can be u s e f u l i n super impos ing LCDC management boun-

d a r i e s o v e r f u n c t i o n a l e c o l o g i c a l u n i t s .

To a l a r g e degree t h e E s t u a r i n e Resources Goal i s a l r e a d y d i r e c t e d

toward t h e use and p r o t e c t i o n o f h a b i t a t s . For example, i t s p e c i f i c a l l y

r e q u i r e s t h a t " a l l ma jo r t r a c t s o f s a l t marsh, t i d e f l a t s , and seagrass and

a l g a e beds" (LCDC 1977b) be i n c l u d e d i n n a t u r a l management u n i t s , w h i l e deep

wa te r h a b i t a t s near s h o r e l i n e s and n a v i g a t i o n channels a r e suggested as

p o t e n t i a l development s i t e s . The emphasis on m a i n t a i n i n g a d i v e r s i t y o f uses

and resources w i t h i n e s t u a r i e s f u r t h e r suggests t h a t t h e range o f h a b i t a t s

should be i d e n t i f i e d i n p l a n n i n g i n v e n t o r i e s , so t h a t examples o f each t y p e

can be p r o t e c t e d i n t h e comprehensive p l a n . The proposed c l a s s i f i c a t i o n system

(F ig . 9) c a t e g o r i z e s t h e d i v e r s i t y o f h a b i t a t s rep resen ted i n Oregon e s t u a r i e s ,

i n c l u d i n g those t h a t a r e s p e c i f i c a l l y ment ioned i n t h e E s t u a r i n e Resources

Goa 1 .

A l though management u n i t boundar ies may be d e f i n e d by h a b i t a t t ypes , i t

i s n o t s u f f i c i e n t t o mere ly p r o t e c t a v a r i e t y o f h a b i t a t s . H a b i t a t s , t h e i r

a s s o c i a t e d communit ies, and t h e processes t h a t c h a r a c t e r i z e them a r e i n t e r -

r e l a t e d . Management based s o l e l y on i n d i v i d u a l h a b i t a t s may n o t p r o t e c t t h e

areas in tended o r p r o v i d e f o r t h e uses t h a t a r e most needed. A c t i v i t i e s i n

a d j a c e n t n a t u r a l and development management u n i t s , f o r example, may be incom-

p a t i b l e due t o t h e i n t e r a c t i o n s between h a b i t a t s and communit ies nearby.

The subsystems i l l u s t r a t e d i n F i g . 7 r e p r e s e n t l a r g e r e c o l o g i c a l u n i t s

c h a r a c t e r i z e d by d i s t i n c t h a b i t a t and community assemblages. The h a b i t a t s

w i t h i n t h e s e subsystems i n t e r a c t and a r e i n f l u e n c e d by an a r r a y o f e n v i r o n -

menta l f a c t o r s such as f l o w , s a l i n i t y , energy regime, sediment type, and

o r g a n i c carbon sources. The d e s i g n a t i o n o f management u n i t s and t h e p o l i c i e s

r e g u l a t i n g t h e i r use must t a k e i n t o account t h e i n t e r a c t i o n s between h a b i t a t s

a t t h e subsystem l e v e l o f o r g a n i z a t i o n .

Shore land and e s t u a r i n e a c t i v i t i e s tend t o be segregated by subsystem.

For example, a g r i c u l t u r a l uses o f t e n o c c u r a l o n g r i v e r i n e subsystems, w h i c h

r e q u i r e d i f f e r e n t management s t r a t e g i e s than mar ine subsystems where commer- I I

c i a 1 development i s o f t e n focused. T h i s a l s o suggests t h a t t h e subsystem may

be t h e l o g i c a l l e v e l f o r management u n i t d e s i g n a t i o n s i n many cases. Resource

i n v e n t o r i e s shou ld i d e n t i f y and c l a s s i f y e s t u a r i e s i n t o subsystems as w e l l as ~ h a b i t a t s t o i d e n t i f y t h e d i v e r s i t y o f subsystem t y p e s and t o a l l o w p lanners

t o s e l e c t t h e most a p p r o p r i a t e fo rm o f management.

E x i s t i n g land and w a t e r uses and t h e d i s t r i b u t i o n o f h a b i t a t s w i t h i n a i l a r g e subsystem may w a r r a n t more than a s i n g l e management d e s i g n a t i o n f o r t h a t

p a r t i c u l a r r e g i o n . F u n c t i o n a l u n i t s o r h a b i t a t assemblages can be i d e n t i f i e d 1 w i t h i n l a r g e subsystems. A ma jo r marsh-mudf la t complex, f o r example, g e n e r a l l y

j u s t i f i e s a d i s t i n c t management d e s i g n a t i o n from t h e dredged channel w i t h i n i t h e same subsystem. P o l i c i e s w i t h i n a g i v e n development u n i t must p r o v i d e f o r

adequate p r o t e c t i o n o f n a t u r a l o r c o n s e r v a t i o n u n i t s w i t h i n the same subsystem.

The LCDC (1977a,b) c l a s s i f i c a t i o n o f e s t u a r i e s and management u n i t s c o n s t i t -

u t e s broad development g o a l s . Management u n i t s a r e e s t a b l i s h e d t o p e r m i t I

development i n s u i t a b l e l o c a t i o n s and t o p r o t e c t o t h e r a reas f rom env i ronmenta l

52

7 I I a l t e r a t i o n and d e g r a d a t i o n a s s o c i a t e d w i t h c o n s t r u c t i o n , f i l l and removal, and

I

commercial and a g r i c u l t u r a l o p e r a t i o n s . However, t h e most comp l i ca ted resource

problems remain a f t e r t h e management u n i t s a r e des igna ted . P o l i c i e s f o r each

u n i t , s i t i n g d e c i s i o n s f o r p a r t i c u l a r development p r o p o s a l s , and performance

s tandards f o r p e r m i s s i b l e uses must c o n s i d e r n o t o n l y d i r e c t h a b i t a t l osses ,

b u t a l s o i n d i r e c t and o f t e n t i m e s s u b t l e e f f e c t s on t h e e s t u a r y as a whole.

The t i m i n g o f p o l l u t a n t d i scharges o r d r e d g i n g i n r e l a t i o n t o m i x i n g and

f l u s h i n g c h a r a c t e r i s t i c s ; t h e s i z e , t i m i n g , and numbers o f p r i v a t e h a t c h e r y

salmon re leased i n an e s t u a r y ; o r t h e c u m u l a t i v e e f f e c t s o f numerous sma l l

a c t i v i t i e s on t h e e n t i r e system ex tend w e l l beyond t h e immediate l o c a t i o n o f

the a c t ' v i t y o r t h e broad management d e s i g n a t i o n govern ing i t .

E s t u a r y p l a n n i n g i n Oregon, l i k e t h e h a b i t a t c l a s s i f i c a t i o n system we

have proposed, rep resen ts a h i e r a r c h y f rom broad t o s p e c i f i c . As p l a n n i n g

advances f rom genera l g u i d e l i n e s t o d e c i s i o n s c o n t r o l l i n g s p e c i f i c p;ojects,

i n c r e a s i n g l y d e t a i l e d resource da ta w i l l be r e q u i r e d . F i g . 1 1 i l l u s t r a t e s

I t h e r e l a t i o n s h i p between e s t u a r y development p l a n s and t h e resource i n f o r -

I ma t ion needed t o e v a l u a t e and implement these p l a n s .

I As we have shown, broad management d e s i g n a t i o n s can be determined on t h e

b a s i s o f r e l a t i v e l y broad i n v e n t o r i e s t h a t c l a s s i f y t h e communit ies, h a b i t a t s ,

and subsystems i n each e s t u a r y . As genera l p o l i c i e s a r e e s t a b l i s h e d w i t h i n

each management u n i t and as s p e c i f i c development p r o p o s a l s a r e made, more I

d e t a i l e d and s i t e - s p e c i f i c i n v e n t o r i e s and c l a s s i f i c a t i o n s wi 1 1 be necessary t o

I e v a l u a t e t h e p o t e n t i a l impact on a g i v e n s i t e . However, env i ronmenta l impact

ana lyses must a l s o c o n s i d e r e f f e c t s beyond t h e immediate area, and s imp le

i n v e n t o r i e s a l o n e a r e n o t s u f f i c i e n t . The more d e t a i l e d q u e s t i o n s o f e s t u a r y -

wide impacts demand p r e d i c t i v e c a p a b i l i t i e s r e q u i r i n g systems a n a l y s i s , m o d e l l i n g

techn iques, and s t u d i e s o f causa l r e l a t i o n s h i p s . Data requ i rements do n o t s t o p

m c "7 m u

m .- C m u .- u .- L m c m y 2 7 .- E u o E m m 0 W I U

m 0 E c a, .- u L m m z 7 m u a m 3 W Y I

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m z yl m 2 " - .- m > > .- m Y

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w i t h t h e resource i n v e n t o r i e s n o r does managemenr cease w i t h t h e d e s g i n a t i o n

o f n a t u r a l , c o n s e r v a t i o n , and development a reas . Research must keep pace

w i t h development p l a n s , p a r t i c u l a r l y as development i n e s t u a r i e s proceeds,

and t h e p o t e n t i a l f o r d e t r i m e n t a l impact t h r o u g h i n t e n s e m u l t i p l e use

inc reases .

PART I I - Resource l n v e n t o r i e s For E s t u a r y

P l a n n i n g and Management

l NTRODUCTI ON

S ince t h e LCDC E s t u a r i n e Resources Goal (1977b) r e q u i res broad management

u n i t d e s i g n a t i o n s and e v a l u a t i o n s o f s i t e - s p e c i f i c development p roposa ls ,

b a s i c p h y s i c a l and b i o l o g i c a l i n f o r m a t i o n about each Oregon e s t u a r y must be

a v a i l a b l e . The goa l i n c l u d e s some genera l g u i d e l i n e s f o r t h e types o f resource

d a t a t h a t shou ld be assembled i n a p l a n n i n g i n v e n t o r y (Tab le I ) , b u t i t does I I

n o t d e t a i l how t h i s i n f o r m a t i o n shou ld be used i n t h e i n v e n t o r y o r t h e compre-

h e n s i v e p l a n . The goal a l s o c a l l s f o r t h e Department o f Land Conserva t ion and

Development (LCDC) w i t h t h e a s s i s t a n c e o f o t h e r agenc ies t o deve lop more

comprehensive i n v e n t o r y g u i d e l i n e s and t o s t a n d a r d i z e methods f o r d a t a c o l -

l e c t i o n . As p a r t o f t h i s p r o j e c t , we have developed a more s p e c i f i c l i s t o f

I e s t u a r y i n v e n t o r y s tandards and have compi led e x i s t i n g i n v e n t o r y d a t a f o r many

Oregon e s t u a r i e s

Tab le 1 . LCDC (1977b) g u i d e l i n e s f o r e s t u a r i n e resource i n v e n t o r i e s .

I n d e t a i l a p p r o p r i a t e t o t h e l e v e l o f development o r a l t e r a t i o n proposed, t h e i n v e n t o r i e s f o r e s t u a r i n e f e a t u r e s shou ld i n c l u d e :

I 1 . P h y s i c a l c h a r a c t e r i s t i c s

A. S i z e , shape, s u r f a c e a rea , and c o n t o u r , i n c l u d i n g w a t e r depths; 0 . Water c h a r a c t e r i s t i c s i n c l u d i n g , b u t n o t l i m i t e d t o , s a l i n i t y ,

tempera tu re , and d i s s o l v e d oxygen. Data shou ld r e f l e c t average and ext reme va lues f o r t h e months o f March, June, September, and December as a minimum; and

C . S u b s t r a t e mapping showing l o c a t i o n and e x t e n t o f rock , g r a v e l , sand, and mud.

2. B i o l o g i c a l c h a r a c t e r i s t i c s L o c a t i o n , d e s c r i p t i o n , and e x t e n t o f :

A. The common spec ies o f b e n t h i c ( I i v i n g i n o r on bot tom) f l o r a and fauna; 0 . The f i s h and w i l d l i f e spec ies , i n c l u d i n g p a r t - t i m e r e s i d e n t s ; C . The i m p o r t a n t r e s t i n g , f e e d i n g , and n e s t i n g areas f o r m i g r a t i n g and

r e s i d e n t s h o r e b i r d s , wading b i r d s and w i l d f o w l ; D . The areas i m p o r t a n t f o r r e c r e a t i o n a l f i s h i n g and h u n t i n g , i n c l u d i n g

a reas used f o r c lam d i g g i n g and c r a b b i n g ; E. E s t u a r i n e we t lands ; F. F i s h and s h e l l f i s h spawning areas; G . S i g n i f i c a n t n a t u r a l areas; and H. Areas p r e s e n t l y i n commercial a q u a c u l t u r e .

RESOURCE INVENTORY GUIDELINES

I n deve lop ing s tandards f o r p l a n n i n g i n v e n t o r i e s , we have c o n c e n t r a t e d on

i n f o r m a t i o n needed t o c l a s s i f y e s t u a r i n e h a b i t a t s and t o d e s c r i b e t h e major

env i ronmenta l f a c t o r s i n f l u e n c i n g p a r t i c u l a r h a b i t a t s and t h e e s t u a r y as a

whole. The i n v e n t o r y s tandards were des igned t o i n c l u d e p h y s i c a l and b i o l o g i -

c a l c h a r a c t e r i s t i c s needed t o d e s i g n a t e management u n i t s and e s t a b l i s h genera l

p l a n n i n g and management p o l i c i e s w i t h i n them.

The g u i d e l i n e s we have suggested do n o t address t h e more d e t a i l e d types

o f research (e.g. e c o l o g i c a l models, b ioassays ) t h a t may be necessary t o

adequa te ly p r e d i c t t h e impact o f a s p e c i f i c p r o p o s a l . These r e s e a r c h needs

w i l l become i n c r e a s i n g l y i m p o r t a n t as t h e e s t u a r y management program i s f u r t h e r

d e f i n e d ( P a r t I , F i g . 11) .

G u i d e l i n e s f o r p h y s i c a l and b i o l o g i c a l resource i n v e n t o r i e s a r e g i v e n i n

Appendix Tables B and C . I n a d d i t i o n t o l i s t i n g t h e e s t u a r i n e d a t a needed,

suggested p l a n n i n g , management, and research a p p l i c a t i o n s o f t h a t da ta a r e

i n c l u d e d . S u i t a b l e methods f o r d a t a c o l l e c t i o n based on p r e v i o u s and proposed

s t u d i e s a r e a l s o b r i e f l y o u t l i n e d . I n those cases where t h e da ta a r e a l r e a d y

a v a i l a b l e f o r many o r a l l Oregon e s t u a r i e s , t h e source o f i n f o r m a t i o n i s

shown .

I n v e n t o r y o f P h y s i c a l C h a r a c t e r i s t i c s

The gu ide1 ines f o r p h y s i c a l da ta ( ~ ~ ~ e n d i x T a b l e B) range f rom genera l

d e s c r i p t i o n s o f t h e e s t u a r y b a s i n t o more s p e c i f i c d e f i n i t i o n s o f t h e processes

o f each e s t u a r y . G e n e r a l l y t h e r e a r e t h r e e ma jo r c r i t e r i a f o r t h e p h y s i c a l

d a t a l i s t e d i n t h e g u i d e l i n e s :

1 ) Many o f t h e d a t a c a t e g o r i e s i n Appendix T a b l e B d i r e c t l y o r i n d i r e c t l y

i n f l u e n c e t h e abundance and d i s t r i b u t i o n o f b i o l o g i c a l communit ies

i n e s t u a r i e s . P h y s i c a l f a c t o r s such as h y d r o l o g i c a l c h a r a c t e r i s t i c s ,

wate r q u a l i t y , o r sediment t y p e a r e necessary t o de te rm ine r e l a t i o n -

s h i p s between spec ies and h a b i t a t d i s t r i b u t i o n s . The p o t e n t i a l i m -

p a c t o f changes i n t h e p h y s i c a l env i ronment shou ld be a p r ime con-

s i d e r a t i o n i n s e l e c t i n g management a l t e r n a t i v e s and e v a l u a t i n g

development p roposa ls .

2) Some o f t h e da ta - -d ra inage a r e a and r i v e r d i scharge , e s t u a r y shape,

s u r f a c e area, and sediment t ype- -a re needed t o a p p l y t h e proposed

e s t u a r y and e s t u a r i n e h a b i t a t c l a s s i f i c a t i o n system ( P a r t I , F i g s . '6

and 9 ) .

3 ) H y d r o l o g i c a l c h a r a c t e r i s t i c s ( c i r c u l a t i o n , m i x i n g , and f l u s h i n g ) a r e

n o t o n l y i m p o r t a n t b i o l o g i c a l l y , b u t a r e needed t o p r e d i c t t h e movement

o f p o l l u t a n t s and t h e e f f e c t s o f l o c a l a l t e r a t i o n s on t h e e s t u a r y .

The f l o w o f wa te r and t h e d i s t r i b u t i o n o f wa te r -bo rn m a t e r i a l s i n

each subsystem de te rm ine whether t h e e f f e c t s o f development w i l l be

l o c a l i z e d o r t r a n s p o r t e d t o o t h e r a reas and whether p o l l u t a n t s w i l l

remain f o r l ong p e r i o d s o r w i l l be q u i c k l y f l u s h e d f r o m t h e e s t u a r y .

4) Past and c u r r e n t wa te r and sediment q u a l i t y d a t a a r e key i n d i c a t o r s

o f t h e env i ronmenta l c o n d i t i o n s o f an e s t u a r y , which shou ld be con-

s i d e r e d by p lanners when e s t a b l i s h i n g s u i t a b l e l o c a t i o n s f o r and t h e

i n t e n s i t y o f f u t u r e development. An ongoing wa te r q u a l i t y sampl ing

program t o c o n t i n u a l l y m o n i t o r t h e e f f e c t o f t h e management program

i s p a r t i c u l a r l y i m p o r t a n t i n e s t u a r i e s c l a s s i f i e d f o r development.

I n v e n t o r y o f B i o l o g i c a l C h a r a c t e r i s t i c s

The d e s i g n a t i o n o f management u n i t s r e q u i r e s judgements concern ing t h e

most a p p r o p r i a t e uses o f s p e c i f i c s i t e s w i t h i n each e s t u a r y . The resource

i n v e n t o r y shou ld i d e n t i f y and d e s c r i b e t h e d i s t r i b u t i o n o f i m p o r t a n t spec ies i n

e s t u a r i n e food c h a i n s . Whenever p o s s i b l e , l i f e h i s t o r i e s and d i s t r i b u t i o n s

5 9

p~

shou ld be c o r r e l a t e d w i t h h a b i t a t s and/or subsystems, so t h a t c r i t i c a l a reas

f o r feed ing, r e p r o d u c t i o n , r e a r i n g , and o t h e r l i f e f u n c t i o n s can be p r o t e c t e d

i n t h e comprehensive p l a n .

The b i o l o g i c a l d a t a suggested f o r a resource i n v e n t o r y a r e shown i n

Appendix Table C . The l i s t i n c l u d e s a l l m a j o r p l a n t and an imal groups t h a t

o c c u r i n t h e sediment o r wa te r column. Among t h e da ta c a t e g o r i e s a r e p l a n t

groups (e.g. marshes, a l g a l and e e l g r a s s beds) t h a t a l s o p r o v i d e h a b i t a t f o r

o t h e r p l a n t and an imal spec ies .

I n a d d i t i o n t o t h e i d e n t i f i c a t i o n and c l a s s i f i c a t i o n o f m a j o r p l a n t groups,

t h e g u i d e l i n e s have a l s o s i n g l e d o u t p l a n t p r o d u c t i v i t y as an i m p o r t a n t f a c t o r I f o r e s t u a r y p l a n n i n g . Because p l a n t s f u n c t i o n as t h e source o f carbon t h a t

f u e l s e s t u a r i n e food c h a i n s , r e l a t i v e p r o d u c t i v i t y o f v a r i o u s p l a n t communit ies I

i s p a r t i c u l a r l y i m p o r t a n t i n managing development e s t u a r i e s . There i s c u r r e n t l y 1

v e r y l i t t l e i n f o r m a t i o n concern ing p l a n t p r o d u c t i o n i n Oregon e s t u a r i e s .

The l i s t o f i n v e n t o r y d a t a i n Appendix Tab le C i s s i m i l a r f o r most groups

o f spec ies and i n c l u d e s b road survey da ta f o r each e s t u a r y t o : I

1 ) i d e n t i f y t h e d i v e r s i t y o f spec ies u t i l i z i n g t h e e s t u a r y ,

2 ) d e s c r i b e t h e seasonal and, i n some cases, h i s t o r i c a l d i s t r i b u t i o n o f

spec ies o r communit ies,

3 ) de te rm ine r e l a t i v e abundance o r biomass o f each spec ies o r community

as an i n d i c a t i o n o f t h e i r c o n t r i b u t i o n t o e s t u a r i n e p r o d u c t i v i t y ,

4 ) c o r r e l a t e wa te r q u a l i t y o r sediment da ta (Appendix T a b l e B ) w i t h

observed d i s t r i b u t i o n s and r e l a t i v e abundance.

I RESEARCH NEEDS FOR OREGON ESTUARIES I

The i n v e n t o r y g u i d e l i n e s i n Appendix Tables B and C p r o v i d e a s tandard

f o r e v a l u a t i n g t h e adequacy o f e x i s t i n g resource d a t a f o r p l a n n i n g and manage- 1 ment o f Oregon e s t u a r i e s . To complete such an e v a l u a t i o n , we have reviewed

I 6 0 I

P h y s i c a l C h a r a c t e r i s t i c s

T a b l e 2 summarizes t h e c u r r e n t p h y s i c a l d a t a f o r Oregon e s t u a r i e s i n

r e l a t i o n t o t h e d a t a c a t e g o r i e s l i s t e d i n t h e i n v e n t o r y g u i d e l i n e s . The m a j o r

i n v e n t o r y needs a r e b r i e f l y h i g h l i g h t e d below:

P h y s i c a l d imens ions

Many Oregon e s t u a r i e s l a c k p u b l i s h e d base maps a t a s c a l e s u f f i c i e n t f o r

p l a n n i n g o r p l a n implementat ion. I n most cases DSL t i d e l a n d maps a t a s c a l e

o f 1:12000 p r o v i d e an adequate p l a n n i n g base. However, these maps do n o t

ex tend t o t h e head o f t i d e o f most e s t u a r i e s , and,consequent ly,do n o t i n c l u d e

t h e e n t i r e e s t u a r y as d e f i n e d by t h e E s t u a r i n e Resources Goal (LCDC 1977b).

There a r e no OSL base maps f o r t h e s m a l l e r s o u t h c o a s t e s t u a r i e s -- t h e E l k ,

S ixes , P i s t o l , and Winchuck. A l though a 1:12000 s c a l e i s g e n e r a l l y adequate

f o r p l a n n i n g purposes, a l a r g e r s c a l e i s p r e f e r a b l e f o r p l a n imp lementa t ion .

P l a n n i n g base maps (1 : 12000) and implementat i o n base maps (1 :3600) which i n c l u d e

t h e e n t i r e e s t u a r y s h o u l d be e s t a b l i s h e d f o r a l l m a j o r Oregon e s t u a r i e s ( P a r t

[ , F i g . I ) .

S u r f a c e a rea measurements f o r many Oregon e s t u a r i e s a r e i n a c c u r a t e due t o

t h e inadequacy o f e x i s t i n g base maps. DSL t i d e l a n d maps a r e drawn t o t h e l i n e

o f Mean H igh Water (MHW), wh ich exc ludes h i g h marshes above t h a t p o i n t . S ince

many o f these maps do n o t ex tend t o t h e head o f t i d e , s u r f a c e area measurements

may be f u r t h e r underes t ima ted . P lanners r e q u i r e a c c u r a t e e s t i m a t e s o f t h e

t o t a l a rea o f each m a j o r h a b i t a t t ype i n each e s t u a r y t o m o n i t o r changes i n

t h e e x t e n t and d i v e r i s t y o f h a b i t a t s and t o d e t e r m i n e a p p r o p r i a t e uses f o r

s p e c i f i c e s t u a r i n e l o c a t i o n s .

Table 2 . Phys ica l and chemical data available f o r major Oregon estuar1es.a

PHYSICAL DIMENSIONS

E s t u a r y B a r e M a p + A n + n n + n A A A o A A A A

Dralnage Awa + + + + + + + + + + + n ~ b + +

Estuary Shape A + + A b i A A A A h

Sur face Area & A A + A A ~ A A A A A A ~ A A

Ua ter Depth A + + + n n i d n n

CLIMATE

Wind ~ O + A A A A A + A A A + A A A

Precipitation + + + + + + + + + + + + + + + +

Fog + A A A +

HYOROLOGICAL CHARACTERISTICS

i T i d a l L e v e l s A A A A A A A @

T i d a l Wave A n + n + + + + A + A

Wind Waves n 4

R i v e r D i s c h a r g e A n A A A ~ A + A A & A A

F l u s h i n g n + h A + A A A h o

M i x i n g d + A A + L L A + A

C i r c u l a t i o n S + d t A d O i l A

WATER QUALITY

L o b b A A + O h b A A h b

A c c ~ e t i o n andc + + + +

+ + A + d A +

A +

.~ -.

e avoi:a.%2e d ~ c h s,2~is:d $!;,? ~jeed.9 <"~rn% 9,: , t : : ~ ~ d i ~ :A:.? 2 0?,8 sugge2:"d. 1 . 1 C 0 , ~ : ~ L e d a m ere indicated h i n de::" (A!. A!? i r m k apsa ia

a?,pro~sriara?, col lec ted or a case i- case h s i s and arc : n e ~ e : o ~ e YO; ean..u-:cd r i z t h i s

I n f o r m a t i o n on t h e depths o f many Oregon e s t u a r i e s i s a l s o l a c k i n g . M~~

soundings f o r Oregon e s t u a r i e s a r e a v a i l a b l e from U.S. Army Corps o f Engineers

(USACE) d r e d g i n g r e p o r t s and N a t i o n a l Ocean Survey (NOS) c h a r t s . These d a t a

~ a r e g e n e r a l l y c o n f i n e d t o t h e lower s u b t i d a l and dredged p o r t i o n s o f l a r g e r

1 I

e s t u a r i e s . Depth i n f o r m a t i o n i s u s e f u l i n unders tand ing b i o l o g i c a l d i s t r i -

I b u t i o n s and observed c i r c u l a t i o n and m i x i n g c h a r a c t e r i s t i c s , m o n i t o r i n g e r o s i o n

1 and d e s p o s i t i o n r a t e s , and s i t i n g proposed f a c i l i t i e s . Depth p r o f i l e s t o t h e ~ head o f t i d e a r e needed f o r most Oregon e s t u a r i e s .

H y d r o l o g i c a l c h a r a c t e r i s t i c s

I The LCDC E s u t a r i n e Resources Goal (1977b) d e f i n e s a number o f e s t u a r i n e ~ boundar ies i n r e l a t i o n t o t i d a l datums. The Oregon E s t u a r i n e H a b i t a t C l a s s i f i -

c a t i o n System ( P a r t I , F i g . 9) employes some o f these same d e f i n i t i o n s , How-

ever , most e x i s t i n g t i d a l i n f o r m a t i o n does n o t cor respond w i t h t h e LOCO

1 d e f i n i t i o n s . The DSL t i d e l a n d maps o n l y show boundar ies f o r MHLI and Mean Low

Water (MLW). For a few l a r g e r e s t u a r i e s , NOS c h a r t s p l o t soundings r e l a t i v e

t o a MLLW datum. There a r e no maps c l e a r l y d e f i n i n g t h e l i n e o f non-aqua t i c

v e g e t a t i o n o r MHHW, as LCOC d e f i n e s t h e u p l a n d / e s t u a r y boundary. A l rhough

h a b i t a t s have been c l a s s i f i e d and mapped f o r most Oregon e s t u a r i e s (ODFW 1978),

i n t e r t i d a l / s u b t i d a l boundar ies a t ELW a r e g ross e s t i m a t e s f rom a e r i a l photos

and f i e l d o b s e r v a t i o n s . T i d e gauges e x i s t i n some of Oregon's l a r g e r e s t u a r i e s

and a d d i t i o n a l gauges shou ld be p laced so t h a t t i d a l boundar ies d e f i n e d by

LCDC can be d r a f t e d on a p p r o p r i a t e base maps.

Most h y d r o l o g i c a l da ta f o r Oregon e s t u a r i e s a r e v e r y ske tchy . Some i n f o r -

mat ion on m i x i n g , c i r c u l a t i o n , and f l u s h i n g a r e c o n t a i n e d i n s t u d e n t theses

f o r s e v e r a l e s t u a r i e s . But these s t u d i e s do n o t i n c l u d e t h e seasonal range

o f f l o w c o n d i t i o n s o r ma jo r t r i b u t a r i e s . The o n l y r e p o r t e d m i x i n g da ta f o r

many e s t u a r i e s a r e from B u r t and M c A l i s t e r (1959) , who c l a s s i f i e d t h e m i x i n g

6 3

t ypes o f Oregon e s t u a r i e s from a v e r y 1 i m i t e d number o f sampl ing p e r i o d s and

s t a t i o n s d u r i n g 1959.

C i r c u l a t i o n and f l u s h i n g c h a r a c t e r i s t i c s a r e b a s i c f o r an unders tand ing

o f b i o l o g i c a l and m a t e r i a l d i s t r i b u t i o n s i n e s t u a r i e s and a r e needed t o e v a l u a t e

t h e s i t i n g and o p e r a t i o n o f proposed developments. A s t a n d a r d p h y s i c a l i n -

v e n t o r y program shou ld be developed t o c h a r a c t e r i z e m i x i n g and c i r c u l a t i o n

p a t t e r n s and f l u s h i n g c h a r a c t e r i s t i c s f o r a l l c o n s e r v a t i o n and development

e s t u a r i e s .

Water qua1 i t y

The Oregon Department o f Envi ronmental Qual i t y (DEQ) m a i n t a i n s a water

q u a l i t y m o n i t o r i n g program f o r Oregon e s t u a r i e s . Data c o l l e c t e d i n c l u d e

temperature , s a l i n i t y , d i s s o l v e d oxygen, BOD, pH, t u r b i d i t y , c o l i f o r m , and

s t r e p t o c o c c i . T i l l a m o o k , Coos, and Yaquina e s t u a r i e s a r e sampled r e g u l a r l y

t h r e e t imes p e r year , w h i l e o t h e r e s t u a r i e s a r e sampled t h r e e t imes every

t h i r d year . Sampl ing s t a t i o n s a r e n o t a lways d i s t r i b u t e d th roughou t t h e

e s t u a r i e s o r on a l l m a j o r t r i b u t a r i e s , w h i c h p r e c l u d e s a f u l l y r e p r e s e n t a t i v e

p r o f i l e o f w a t e r qua1 i t y .

I d e a l l y , a wa te r q u a l i t y m o n i t o r i n g program s h o u l d sample c o n s e r v a t i o n

and development e s t u a r i e s s e a s o n a l l y . Sampling s h o u l d i n c l u d e upper r i v e r i n e

s e c t i o n s t o e s t i m a t e n o n - p o i n t sources o f p o l l u t i o n f r o m a g r i c u l t u r a l and o t h e r

l a n d uses. C o n d i t i o n s i n r i v e r i n e and s lough subsystems d u r i n g p e r i o d s o f low

f l o w and poor f l u s h i n g may be p a r t i c u l a r l y i m p o r t a n t . I n development e s t u a r i e s ,

annual o r semi-annual surveys c o v e r i n g 24-hour p e r i o d s a t a few s e l e c t s i t e s

would h e l p t o document d a i l y f l u c t u a t i o n s i n wa te r q u a l i t y . Because many

w a t e r q u a l i t y parameters a r e a l s o i m p o r t a n t t o b i o l o g i c a l and p h y s i c a l surveys,

m o n i t o r i n g programs shou ld be des igned t o maximize t h e i r v a l u e t o e s t u a r i n e

r e s e a r c h e r s . S a l i n i t y p r o f i l e s f rom s u r f a c e t o bo t to rn , fo r example, c o u l d be

v a l u a b l e i n c h a r a c t e r i z i n g seasonal m i x i n g processes

6 4

Sediments

Sediment p a r t i c l e s i z e and o r g a n i c c o n t e n t a r e ma jo r f a c t o r s i n f l u e n c i n g

b e n t h i c community compos i t i on and d i s t r i b u t i o n i n e s t u a r i e s . S ince many f i s h

feed h e a v i l y on b e n t h i c organisms, t h e i r d i s t r i b u t i o n i s i n d i r e c t l y r e l a t e d t o

sediments as w e l l . The Oregon E s t u a r i n e H a b i t a t C l a s s i f i c a t i o n System ( P a r t I ,

F i g . 9 ) r e l i e s on sediment t y p e as a p r i m a r y f a c t o r d e f i n i n g e s t u a r i n e h a b i -

t a t s and a s s o c i a t e d communit ies, wh ich a r e e s s e n t i a l c o n s i d e r a t i o n s i n i

e s t u a r i n e p l a n n i n g . Sediment t y p e and qua1 i t y a r e a l s o i m p o r t a n t d a t a t o cbn-

s i d e r i n dredge d i s p o s a l p l a n n i n g i n development e s t u a r i e s .

Sediment d i s t r i b u t i o n has been s t u d i e d i n some d e t a i l i n T i l l a m o o k ( A v o l i o

1973) , N e t a r t s ( S t o u t 1976), and Yaquina ( ~ u l m and Byrne 1967) e s t u a r i e s .

Surveys o f c lam beds i n many e s t u a r i e s p r o v i d e q u a l i t a t i v e da ta on s u b s t r a t e

d i s t r i b u t i o n . Sediment t ypes shown on ODFW h a b i t a t maps (1978) r e f l e c t da ta

f r o m t h e l i t e r a t u r e on q u a l i t a t i v e o b s e r v a t i o n s , Complete sediment s,drveys

s h o u l d be conducted i n c o n j u n c t i o n w i t h b e n t h i c i n v e r t e b r a t e s t u d i e s , p a r t i -

I c u l a r l y i n c o n s e r v a t i o n and development e s t u a r i e s .

B i o l o g i c a l C h a r a c t e r i s t i c s

Tab le 3 i n d i c a t e s a l a r g e gap o f b a s i c i n v e n t o r y i n f o r m a t i o n on many p l a n t l

and animal groups i n Oregon e s t u a r i e s . The most n o t a b l e d e f i c i e n c i e s a r e

b r i e f l y desc r ibed below:

S t u d i e s o f p h y t o p l a n k t o n and b e n t h i c m i c r o - and macroa lga l communit ies a r e

p r i m a r i l y s c a t t e r e d among s t u d e n t r e p o r t s and theses f o r a Few e s t u a r i e s

H a b i t a t maps c l a s s i f y i n g a l g a l " a q u a t i c beds" (ODFW 1978) a r e based on a e r i a l

photos and f i e l d o b s e r v a t i o n s f rom o n l y a s i n g l e summer. The LCDC E s t u a r i n e

Resources Goal (197713) emphasizes t h a t a l l ma jo r a l g a l beds shou ld be i n c l u d e d

i n a n a t u r a l management d e s i g n a t i o n . D e s p i t e t h e assumed impor tance o f a l g a l

6 5

• able 3. ~ ~ ~ l o g l c a l d a t a a v a ~ l a b l e f a r maJor Oregon estuar1es.a

MLCROALGRE

Conmuni t i e s and d i s t r i b u t i o n

P r o d u c t i v i t ~

WCROALME

Comnuni t i e r and d i s t r i b u t i o n t

Associated animal s p e c i e s

Pmduct iv i tY

SEAGRASS

. Cornunit ies and d i s t r i b u t i o n c

Associated animal s p e c i e s

Produc t iv i ty

TIDAL MARSHES

Comnuni t i e s A + A + A ~ A ~ A A A A + A A and d i s t r l h u t i a n

A Diked marsh

His tor i ca1 + + + d A A change

A Associated + animal s p e c i e s

+ A Praduc t iv i t y

ZOOPLANKTON

Comnuni t i e r and d i s t r i b u t i o n

Other n A b e n t h i c i n v e r t .

F I S H

Comuni t i e s A A + A ~ A A A + A + + A A A Q and d i s t r i b u t i o n

F i s h i n g A b A A A A A A A A A ~ A A areas

BIRDS

Bird watching A areas

M W L S

Mar ine species L + + A n + h A + T e r r e s t r i a l r;eclei . + .. A

- ~

L szus (+1 i s shorn whare ~ n i a i r e a v s i i z h i e uhich satrspd m:s needs cozuim; of ~ ~ > p e i d i r i_tbze c U V ~ haoi

been cal lea ted bj methods sugge6:ad. Incomq7leta dnaa arc i n d i c l t e d by a d e l t a (0:. 412 blank sjn?es

r d i c a t e t h a t data are unre2iabLe UP absent.

~ l z n z beds are dezireated on base -ape fro a22 es tuar ies (ODFW 2 0 7 6 J

O Eelgrass beds are ic i inoazed or. ~ s e ~ r p s ,<or a i l i s t u a ~ i e s IODFU 2.0161.

d so eezg;.;ss is for tfra .~oyue mid c~tecco estuaries

ieaearch i n progress on prod~ctivit~andinurri~brctennd f i s h u t i l i z a t i o n of Neimts and S i l e t z marshas

Illorgan and RoZton 29771.

communi t ies a t t h e base o f food c h a i n s i n Oregon e s t u a r i e s , t h e r e have been no

e x t e n s i v e q u a n t i t a t i v e surveys o f t h e seasonal d i s t r i b u t i o n , compos i t i on , b i o -

mass, o r p r o d u c t i v i t y o f m i c r o - o r macroa lga l communit ies. Nor has t h e impor-

tance o f v a r i o u s macroa lga l communit ies as h a b i t a t f o r i n v e r t e b r a t e s , f i s h ,

and b i r d s been s t u d i e d .

Seagrasses

Ee lg rass spec ies have a l s o r e c e i v e d l i t t l e research a t t e n t i o n i n Oregon

The U.S . Env i ronmenta l P r o t e c t i o n Agency (€PA) i s c u r r e n t l y s t u d y i n g t h e

p r o d u c t i v i t y o f Zostera mar ina i n t h e N e t a r t s and S i l e t z e s t u a r i e s (Morgan and

H o l t o n 1977). ODFW h a b i t a t maps (1978) i n d i c a t e approx imate summer d i s t r i b u t i o n

f rom a e r i a l photos and f i e l d o b s e r v a t i o n s . However, seasonal changes i n cover

and biomass have n o t been documented, n o r have c o n c u r r e n t changes i n a s s o c i a t e d

b e n t h i c spec ies been s t u d i e d . There has been no research i n Oregon on a second

spec ies o f e e l g r a s s , Z . n a n a , which has been d iscovered a t h i g h e r i n t e r t i d a l

e l e v a t i o n s i n a number o f e s t u a r i e s . Bas ic seasonal surveys o f e e l g r a s s d i s -

t r i b u t i o n , biomass, and a s s o c i a t e d animal spec ies a r e needed f o r most Oregon

e s t u a r i e s .

T i d a l marshes

J e f f e r s o n (1975; Ak ins and J e f f e r s o n 1973) has conducted broad surveys o f

s a l t marsh communit ies i n Oregon e s t u a r i e s . ODFW h a b i t a t maps (1978) show t h e

approx imate d i s t r i b u t i o n o f h i g h and low s a l t , f r e s h , and shrub marshes.

However, n e i t h e r o f these sources map d i s t r i b u t i o n t o t h e head o f t i d e on a l l

e s t u a r i e s . The r e s u l t s o f c u r r e n t €PA s t u d i e s o f marsh p r o d u c t i v i t y (Morgan

and H o l t o n 1977) i n t h e S i l e t z and N e t a r t s e s t u a r i e s may be a p p l i e d t o o t h e r

e s t u a r i e s i f biomass o r d e n s i t y o f cover a r e determined f o r s i m i l a r marsh

types i n these o t h e r systems.

Tremendous expanses o f s a l t marsh have been d i k e d i n Oregon, p r o d u c i n g a

s i g n i f i c a n t impact on many e s t u a r i e s . There have been no comprehensive su rveys

o f d i k e d marshes t o t h e head o f t i d e on most Oregon e s t u a r i e s , a l t h o u g h some

have been i d e n t i f i e d on ODFW h a b i t a t maps (1978). Breach ing d i k e s on s a l t

marshes i s a p o s s i b l e method o f h a b i t a t r e s t o r a t i o n o r m i t i g a t i o n f o r e s t u a r y

f i l l i n g as s p e c i f i e d i n t h e LCDC E s t u a r i n e Resources Goal (1977b). Surveys

shou ld document t h e l o c a t i o n and ownersh ip o f d i k e d marshes, t h e s t a t e o f

r e p a i r o r d i s r e p a i r o f d i k e s and t i d e g a t e s , and t h e spec ies compos i t i on and'

s tage o f success ion f o r each d i k e d marsh community. S tud ies a r e needed t o

e v a l u a t e t h e impact o f d i k e removal and t o compare t h e u t i l i z a t i o n o f d i k e d and

und iked qarshes by b i r d s , mammals, and i n v e r t e b r a t e s . A s tudy o f t h e Salmon

R i v e r e s t u a r y (.Morgan and Hol t o n 1977) w i 1 i p r o v i d e d a t a concern ing p l a n t

success ion i n a h i g h marsh f o l l o w i n g d i k e b reach ing , b u t a d d i t i o n a l research i s

r e q u i r e d t o document changes i n animal u t i l i z a t i o n a f t e r removing d i \ .es on t h i s

and o t h e r marsh t ypes .

Zooplankton and i n v e r t e b r a t e s

Zooplankton surveys a r e a v a i l a b l e f rom r e p o r t s and theses f o r t h e N e t a r t s

(Zimmerrnan 1972), Yaquina ( F r o l a n d e r e t a l . 1973; Zimmerman i 9 7 2 ) , and A lsea

(Matson 1972) e s t u a r i e s o n l y . S t u d i e s o f t h e d i s t r i b u t i o n and abundance o f

l a r v a l c r a b and clam spec ies would be v a l u a b l e f o r most e s t u a r i e s . Crab l a r v a e

a r e abundant i n many e s t u a r i e s d u r i n g t h e summer, b u t t h e growth and s u r v i v a l

o f c rabs from l a r v a e t o a d u l t s i n Oregon e s t u a r i e s has n o t been s t u d i e d .

Most b e n t h i c i n v e r t e b r a t e surveys have been r e s t r i c t e d t o a d u l t clams and

1 c rabs . ODFW has been c o n d u c t i n g surveys o f c lam and shr imp p o p u l a t i o n s i n many

e s t u a r i e s (Hancock e t a l . 1979). However, i n f o r m a t i o n concern ing age c l a s s e s ,

h a r v e s t r a t e s , and spawning p e r i o d s i s l a c k i n g f o r most systems. ODFW resource

use surveys (e.g. Gaumer e t a l . 1973) p r o v i d e c r a b h a r v e s t da ta by summer month

6 9

for many e s t u a r i e s , b u t t h e d i s t r i b u t i o n , r e l a t i v e abundance, s i z e c l a s s , and

annual v a r i a b i l i t y i n t h e s p o r t c a t c h o f Dungeness (cancer rnag is ter ) and r e d

rock ( c . productus) c r a b s have n o t been documented.

There have been few genera l surveys o f b e n t h i c i n v e r t e b r a t e communit ies

i n Oregon. L i m i t e d i n f o r m a t i o n i s a v a i l a b l e f rom s t u d e n t r e p o r t s and theses f o r

N e t a r t s ( S t o u t 1976), Yaquina arkha ham 19671, and Coos ( J e f f e r t s 1977; USACE

1975) e s t u a r i e s . Because changes i n t h e e s t u a r y bot tom b rough t about by

d redg ing , f i l l i n g , a l t e r a t i o n o f f l o w p a t t e r n s , and o t h e r d i s t u r b a n c e s have a

d i r e c t e f f e c t on t h e b e n t h i c community i n t h e area, i n f o r m a t i o n concern ing t h e

compos i t i on , d i s t r i b u t i o n , and abundance o f b e n t h i c i n v e r t e b r a t e s i s e s s e n t i a l

f o r p lanners t o d e s i g n a t e a p p r o p r i a t e uses f o r p a r t i c u l a r s i t e s i n t h e e s t u a r y .

The i d e n t i f i c a t i o n o f c h a r a c t e r i s t i c i n v e r t e b r a t e assemblages i s a l s o needed

t o d e f i n e t h e ma jo r t ypes o f h a b i t a t s t h a t occur i n Oregon e s t u a r i e s .

F i s h - There have been a number o f s t u d i e s o f f i s h communit ies i n Oregon e s t u a r i e s .

A 2 .5-year survey was completed on T i l larnook Bay ( ~ o t t o m and Forsberg 1978;

Forsberg e t a l . 1977). Less e x t e n s i v e sampl ing programs were conducted on t h e

Coos (Cummings and Schwartz 1971 ; H o s t i c k 1975), Umpqua ( ~ u l l e n 1977), and

N e t a r t s ( S t o u t 1976) systems. ODFW annual surveys have been conducted on t h e

S ius law, Unpqua, and Coos e s t u a r i e s ; and a 6-month s tudy o f Yaquina Bay f i s h e s

was completed by EPA; however, t h e r e s u l t s o f these surveys have n o t y e t been

p u b l i s h e d . ODFW a l s o completed s p o r t f i s h i n g c r e e l surveys f o r many Oregon

e s t u a r i e s (e.g. Gaumer e t a l . 1973), and t h e r e a r e p l a n s t o update these i n

1981. Most o t h e r ODFW f i s h s t u d i e s have been r e l a t e d t o salmonids and ha tchery

o p e r a t i o n s (e.g. Reimers 1974) . The o n l y p u b l i s h e d survey o f l a r v a l f i s h e s was

conducted on t h e Yaquina e s t u a r y (Pearcy and Myers 1974). Other s t u d i e s on

Y a G i n a Bay have emphas i z e d p a r t i c u l a r spec ies o f i n t e r e s t ( B e a r d s l e ~ 1969;

Gnose 1968).

7 0

D e s p i t e these r e c e n t e f f o r t s t o c a t a l o g and d e s c r i b e e s t u a r i n e f i s h e s ,

genera l su rveys c o v e r i n g annual p e r i o d s a r e l a c k i n g f o r many Oregon e s t u a r i e s .

Where b road i n v e n t o r i e s have been conducted, spec ies o f i n t e r e s t need t o be de- ll i

f i n e d i n o r d e r t o complete in -dep th s t u d i e s o f l i f e h i s t o r y , food h a b i t s , and

h a b i t a t requ i rements . Concurrent s t u d i e s o f food h a b i t s and b e n t h i c o r e p i -

fauna l i n v e r t e b r a t e d i s t r i b u t i o n s a r e needed t o de te rm ine f e e d i n g h a b i t a t s f o r

es tua r ine -dependen t spec ies , As f i s h su rveys a r e completed f o r a v a r i e t y o f

e s t u a r y t ypes , spec ies compos i t i on , abundance, and d i s t r i b u t i o n shou ld be com-

pared w i t h t h e h a b i t a t t ypes i n each s t ream t o h e l p de te rm ine t h e h a b i t a t r e -

qu i rements o f f i s h e s found i n Oregon e s t u a r i e s .

B i r d s and mammals

I n v e n t o r y i n f o r m a t i o n concern ing b i r d s and mammals o f Oregon e s t u a r i e s i s

n o t e x t e n s i v e . L i t t l e q u a n t i t a t i v e da ta a r e a v a i l a b l e f o r e s t u a r i n e use by

w a t e r f o w l and s h o r e b i r d s . Most da ta c o n s i s t o f spec ies l i s t s , sometimes i n -

d i c a t i n g qua1 f t a t i v e c a t e g o r i e s o f r e l a t i v e abundance ( ~ a t t e r s o n 1971 ; Bayer

1978). The USACE Wetlands Reviews f o r t h e A lsea (USACE 1976a), Nehalem (USACE

1976b), and S i l e t r (USACE 1 9 7 6 ~ ) e s t u a r i e s l i s t presence o r absence o f spec ies

by h a b i t a t t y p e . I n f o r m a t i o n concern ing s p e c i f i c h a b i t a t requ i rements i s v e r y

l i m i t e d . Water fowl h u n t i n g and b i r d wa tch ing may a l s o be i m p o r t a n t c o n s i d e r a t i o n s

i n comprehensive e s t u a r y p l a n s , b u t p u b l i s h e d i n f o r m a t i o n i s l a c k i n g .

Data c o n c e r n i n g mar ine mammals i n Oregon a r e a l s o g e n e r a l l y q u a l i t a t i v e

(USACE 1976a,b,c). Ongoing s t u d i e s o f p o p u l a t i o n , growth, and f e e d i n g h a b i t s

o f h a r b o r s e a l s i n N e t a r t s and Rogue e s t u a r i e s (Morgan and H o l t o n 1977) w i l l

p r o v i d e t h e most q u a n t i t a t i v e i n f o r m a t i o n t o d a t e concern ing t h e u t i l i z a t i o n

o f e s t u a r i e s by mar ine mammals

A l though t h e r e a r e q u a l i t a t i v e l i s t i n g s o f t e r r e s t r i a l mammals f o r s e v e r a l

e s t u a r i e s (e .g . USACE 1976 a,b,c) , community c o m p o s i t i o n and abundance by h a b i -

t a t t y p e a r e g e n e r a l l y u n a v a i l a b l e .

7 1

-~ -~~~

Research P r i o r i t i e s

AS p l a n n i n g proceeds and development g o a l s i d e n t i f i e d i n l o c a l p l a n s a r e

implemented, b a s i c i n v e n t o r y d a t a w i l l become i n c r e a s i n g l y i m p o r t a n t t o a l l

l o c a l , s t a t e , and f e d e r a l agenc ies i n v o l v e d i n e s t u a r y management. A s tandard,

c o o r d i n a t e d i n v e n t o r y program t o p r o v i d e t h i s i n f o r m a t i o n i s e s s e n t i a l t o ensure

t h a t t h e most p r e s s i n g r e s e a r c h needs have p r i o r i t y , t h a t r e s e a r c h t i m e and

d o l l a r s a r e spent most e f f e c t i v e l y , and t h a t r e s u l t s a c h i e v e a h i g h degree o f

t r a n s f e r a b i l i t y . The Oregon E s t u a r i n e Research C o u n c i l , composed o f s t a t e and.

f e d e r a l agenc ies and i n s t i t u t i o n s , c o u l d h e l p t o c o o r d i n a t e r e s e a r c h e f f o r t s

and p r e v e n t d u p l i c a t i o n i n f u t u r e e s t u a r y i n v e n t o r i e s .

E s t a b l i s h i n g p r i o r i t i e s f o r e s t u a r i n e resource i n v e n t o r i e s i n Oregon i s

d i f f i c u l t , s i n c e t h e l i s t o f da ta needed i s b o t h l o n g and broad. L i f e h i s t o r y

s t u d i e s , p r i m a r y p r o d u c t i v i t y measurements, and h y d r o l o g i c and faunal surveys

a r e a l l i m p o r t a n t research needs a t t h i s e a r l y s t a g e o f e s t u a r y p l a n n i n g and

management. To d a t e t h e most e x t e n s i v e research has been on l a r g e development

systems, i n c l u d i n g Coos, T i l l a m o o k , and Yaquina e s t u a r i e s . Among c o n s e r v a t i o n

e s t u a r i e s , t h e most comprehensive i n v e n t o r i e s a r e f r o m t h e USACE Wetlands

Reviews f o r t h e A lsea (USACE 1976a), S i l e t z (USACE 1976c), and Nehalem (USACE

1976b) systems and a s t u d e n t research p r o j e c t on t h e N e t a r t s e s t u a r y ( S t o u t

1976). G e n e r a l l y , t h e r e has been v e r y l i t t l e r e s e a r c h on t h e s m a l l e r sou th

coas t e s t u a r i e s c l a s s i f i e d by LCDC (1977a) f o r development o r c o n s e r v a t i o n .

The p o t e n t i a l and p r e s s u r e f o r development o f these systems combined w i t h t h e

l a c k o f a v a i l a b l e resource da ta suggest t h a t t h e f o l l o w i n g e s t u a r i e s r e c e i v e

t h e h i g h e s t p r i o r i t y f o r research : S ius law, Umpqua, C o q u i l l e , Rogue, and Chetco.

Among c o n s e r v a t i o n e s t u a r i e s , t h e Necanicum and Nestucca a r e i n g r e a t e s t need

o f i n v e n t o r y work.

A l though t h e r e i s more immediate need f o r research on p a r t i c u l a r deve lop-

I ment and c o n s e r v a t i o n e s t u a r i e s , n a t u r a l systems may p r o v i d e t h e b e s t

I I

~~~

o p p o r t u n i t y f o r s t u d i e s o f u n d i s t u r b e d h a b i t a t s o r communit ies. Smal

a l t e r e d systems may be v e r y u s e f u l f o r m o d e l l i n g and s t u d i e s o f f a c t o r s i n -

f l u e n c i n g spec ies d i s t r i b u t i o n s . R e s u l t s o f t h i s research may be a p p l i e d and

t e s t e d i n l a r g e r , more complex systems.

Research des ign and methods t h a t p r o v i d e i n f o r m a t i o n wh ich i s u s e f u l beyond

t h e immediate focus o f a p a r t i c u l a r research p r o j e c t may be as i m p o r t a n t as

t h e s p e c i f i c s u b j e c t m a t t e r o f t h e s tudy . Standard methods f o r c o l l e c t i n g ,

a n a l y z i n g , and r e p o r t i n g e c o l o g i c a l da ta a r e needed so t h a t r e s u l t s a r e com-

p a r a b l e f rom one s tudy s i t e t o a n o t h e r . H a b i t a t c l a s s i f i c a t i o n p r o v i d e s a

s t a n d a r d means o f o r g a n i z i n g resource i n v e n t o r i e s and survey f i n d i n g s and

assembles t h e i n f o r m a t i o n i n a h i g h l y u s a b l e f o r m f o r p l a n n e r s and resource

managers. R e p r e s e n t a t i v e e s t u a r y types shou ld be s e l e c t e d t o maximize t h e

a p p l i c a t i o n o f f i n d i n g s t o o t h e r s i m i l a r e s t u a r i e s and t o d e f i n e subsystem

hab i ta t -commun i ty a s s o c i a t i o n s t h a t w i l l v e r i f y o r m o d i f y t h e Oregon E s t u a r i n e

H a b i t a t C l a s s i f i c a t i o n System ( P a r t I , F i g . 9 ) . The c l a s s i f i c a t i o n o f e s t u a r y

types ( P a r t I , F i g . 6) may be u s e f u l i n s e l e c t i n g a p p r o p r i a t e e s t u a r i e s f o r

t h i s research

The t i m i n g o f research a c t i v i t y i s e q u a l l y c r i t i c a l . Surveys o f impact

s t u d i e s f r e q u e n t l y a r e i n i t i a t e d long a f t e r development p l a n s a r e w e l l under-

way. As a r e s u l t , f i n d i n g s o f t e n l a g beh ind t h e i m p o r t a n t phases o f d e c i s i o n -

making. Impact s t u d i e s shou ld n o t be c o n f i n e d t o s h o r t - t e r m analyses o f

s p e c i f i c a l t e r a t i o n s b u t shou ld a l s o assess l o n g - t e r m e f f e c t s o f development

p r o j e c t s and t h e c u m u l a t i v e r e s u l t s o f a l a r g e number o f a c t i v i t i e s . Standard

i n d i c a t o r spec ies shou ld be s e l e c t e d f o r b ioassay8 and s t u d i e s t o m o n i t o r c h r o n i c

impacts and t h e s y n e r g i s t i c e f f e c t s o f i n c r e a s i n g l e v e l s o f development i n

e s t u a r i e s .

A combined program o f broad i n v e n t o r i e s f o r genera l p l a n n i n g a p p l i c a t i o n s

t o g e t h e r w i t h d e t a i l e d research on e s t u a r i n e processes and t h e impact o f

7 3

alterations would best serve immediate and long-term planning needs in Oregon

However, a monitoring program should continue so the management

strategies implemented for each estuary can be evaluated and revised where

necessary.

I LITERATURE CITED I 'I

Ak ins , G. and C. J e f f e r s o n . 1973. Coasta l we t lands o f Oregon; a n a t u r a l re - source i n v e n t o r v r e p o r t . Oreq. Coast. Conserv. Dev. Comm. F lo rence . - 159 PP.

A v o l i o , G. 1973. Granu lomet r i c a n a l y s i s o f r e c e n t sediments o f T i l l a m o o k Bay, 1 Oregon. M.S. Thes is , P o r t l a n d S t a t e Univ . , P o r t l a n d . 67 pp.

i B a t t e r s o n , W. 1971. Nestucca Bay, c o n f l i c t s i n e s t u a r y uses. Oreg. S t a t e

I Game Comm. Spec ia l Rep.

I I

Bayer, R. 1978. B i r d s o f L i n c o l n County, Oregon. Sea Grant Mar ine A d v i s o r y

I Program. Oreg. S t a t e U n i v . , Newport. 19 pp.

Beards ley , A. 1969. Movement and a n g l e r use o f f o u r f o o d f i s h e s i n Yaquina Bay, Oregon. Ph.D. Thes is , Oreg. S t a t e U n i v . , C o r v a l i i s . 173 pp.

t I Bottom, D. and B. Forsberg. 1978. The f i s h e s o f T i l l a m o o k Bay. Oreg. Dep.

F i s h W i l d l . 56 pp.

B u r t , W.and W . M c A l i s t e r . 1959. Recent s t u d i e s i n t h e hydrography o f Oregon e s t u a r i e s . F i s h Comm. Oreg. Res. B r i e f s 7 (1 ) :14 -27 .

C a r r i k e r , M . 1967. Ecoloqy o f e s t u a r i n e b e n t h i c i n v e r t e b r a t e s : a o e r s p e c t i v e . Pp. 442-4871n G . H . L a u f f (ed . ) , E s t u a r i e s . Pub. No. 83, American A s s o c i a t i o n f o r t h e Advancement o f Sc ience, Wash., 0. C .

C l a r k , J. i 9 7 7 Coasta l ecosystem management, a t e c h n i c a l manual f o r t h e c o n s e r v a t i o n o f c o a s t a l zone resources. The Conserva t ion Foundat ion. John Wi ley and Sons, New York . 928 p p .

C l i f t o n , H. , R. P h i l l i p s , and R. Hunter . 1973. D e p o s i t i o n a l s t r u c t u r e and processes i n t h e mouths o f sma l l c o a s t a l st reams, southwest Oregon. Pp. 115-140 I n D . R . Coates ( e d . ) , Coasta l Geomorphology, Binghamton, N . Y .

Cowardin, L . , V . C a r t e r , F. G o l e t , E . LaRoe. 1977. C l a s s i f i c a t i o n o f we t lands and deep-water h a b i t a t s o f t h e U n i t e d S t a t e s (an o p e r a t i o n a l d r a f t ) . J . H . Sather ( e d . ) . U . S . F i s h and W i l d l i f e S e r v i c e . 100 pp.

Cummings, T. and E. Schwartz. 7971. F i s h i n Coos Bay, Oregon, w i t h comments on d i s t r i b u t i o n , tempera tu re and s a l i n i t y o f t h e e s t u a r y . F i s h Comm. Oreg.

85 PP.

Dicken, S . 1965. Oregon geography, t h e people , t h e p l a c e , t h e t i m e . 4 t h e d i t i o n Dep. Georgr . , Un iv . Oreg., Edwards B r o t h e r s , i n c . , Ann Arbor , Mich. 147 PP.

Dunford, W . 1972. Space and food u t i l i z a t i o n by sa lmonids i n marsh h a b i t a t s o f t h e F raser R i v e r e s t u a r y . M . S . T h e s i s , Un iv . B r i t i s h Columbia, Vancouver. 81 pp.

Forsberg, B . , J . Johnson, and S . K lug . 1975. I d e n t i f i c a t i o n , d i s t r i b u t i o n , and

notes on food h a b i t s o f f i s h and s h e l l f i s h i n T i l l a m o o k Bay, Oregon. Oreg. Dep. F i s h W i l d l . 85 pp.

F ro lander , H., C . M i l l e r , M. F l ynn , S . Myers, and S . Zimmerman. 1973. Seasonal c y c l e s o f abundance i n zoop lank ton p o p u l a t i o n s o f Yaquina Bay, Oregon. School o f Oceanography, Oreg. S t a t e Un iv . , C o r v a l l i s . 14 pp.

Gaumer, T . , D . Demory, and L . Osis. 1973. A lsea R i v e r e s t u a r y resource use s tudy , 1971. F i s h Comm. Oreg.

Gnose, C . 1968. Ecology o f t h e s t r i p e d seaperch, E m b i o t i c a l a t e r a l i s , i n Yaquina Bay, Oregon. M. S . Thes is . Oreg. S t a t e Un iv . , C o r v a l l i s . 53 pp.

Hancock, D . , T. Gaumer, G . W i l l e k e , G . Robar t , and J . F lynn . 1979. S u b t i d a l ~

c lam p o p u l a t i o n s : d i s t r i b u t i o n , abundance, and eco logy . OSU Sea Grant program, C o r v a l l i s . 243 pp.

Hedgpeth, J . 1957. Mar ine biogeography. Pp. 359-382 In Hedgpeth (ed . ) , T r e a t i s e on Mar ine Ecology and Paleoeco logy, Vo l . 1 , GSA Memoir 67.

H o s t i c k , G . 1975. Numbers o f f i s h cap tu red i n beach s e i n e h a u l s i n Coos R i v e r e s t u a r y , Oregon, June th rough September 1970. F i s h Comm. Oreg., Coasta l R i v e r s I n v e s t . I n f . Rep. 74-11. 22 pp.

Howard, Needles, Tammen and Bergendof f Co. 1975. Wetlands r e v i e w o f S i l e t z Bay, Oregon. P r e l i m i n a r y D r a f t , U .S . Army Corps o f Engineers , P o r t l a n d , Oregon.

J e f f e r s o n , C . 1975. P l a n t communit ies and success ion i n Oregon c o a s t a l s a l t marshes. Ph.D. T h e s i s . Oreg. S t a t e U n i v . , C o r v a l l i s . 192 pp.

J e f f e r t s , K. 1977. The v e r t i c a l d i s t r i b u t i o n o f i n f a u n a : a comparison o f dredged and undredged areas i n Coos Bay, Oregon. M . S . T h e s i s . Oreg. S t a t e Un iv . , C o r v a l l i s . 145 pp.

Kulm, L. and J . Byrne. 1967. Sediments o f Yaquina Bay, Oregon. Pp. 226-238. In G . H . L a u f f (ed . ) , E s t u a r i e s . Pub. no. 83, American A s s o c i a t i o n f o r t h e Advancement o f Sc ience, Wash., 0. C .

Markham, J . 1967. A s tudy o f t h e na ima ls i n h a b i t i n g l a m i n a r i a n h o l d f a s t s i n Yaquina Bay, Oregon. M. A. T h e s i s , Oreg. S t a t e U n i v . , C o r v a l l i s . 62 pp.

Matson, A. 1972. Zooplankton and hydrography o f A lsea Bay, Oregon, September 1966 t o September 1968. Ph.0. Thes is , Oreg. S t a t e U n i v . , C o r v a l l i s .

M i l l e r , B. and E. McRae. 1978. H e r r i n g spawning survey Coos Bay, Oregon, w i n t e r 1977-78 Oreg. Dep. F i s h W i l d l . 10 pp.

Morgan, J. and R. H o l t o n . 1977. A compendium o f c u r r e n t research and management programs concern ing Oregon's e s t u a r i e s . Oregon E s t u a r i n e Research Counc i l Pub. no. 2 , Oreg. S t a t e U n i v . , C o r v a l l i s .

Mu l len , R . 1977. The occur rence and d i s t r i b u t i o n o f f i s h i n t h e Umpqua R i v e r e s t u a r y , June t h r o u g h October 1972. Oreg. Oep. F i s h W i l d l . , I n f . Rep. F i s h . no. 77-3. 39 pp.

~ -~ 7

I I I

N i e r i n g , W. and R. Warren. 1977. S a l t marshes. Pp. 697-702 in C l a r k , Coas ta l ecosystem management, a t e c h n i c a l manual f o r t h e conservation o f c o a s t a l zone resources . The C o n s e r v a t i o n Founda t ion , John W i l e y and Sons, New York.

Odum, H . , B . Copeland, E. McMahan. 1974. C o a s t a l E c o l o g i c a l Systems o f t h e U n i t e d S t a t e s . The C o n s e r v a t i o n Founda t ion . Washington D.C. Four volumes.

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Oregon Land C o n s e r v a t i o n and Development Commission. 1977 b . S t a t e w i d e p l a n n i n g g o a l s and g u i d e l i n e s . Salem.

Pearcy, W . and S . Myers. 1974. L a r v a l f i s h e s o f Yaquina Bay, Oregon: a n u r s e r y ground f o r rnar ine f i s h e s ? F i s h B u l l . 72 (1) :201-213.

Percy , K., C . S u t t e r l i n , D . B e l l a , and P. Kl ingeman. 1974. D e s c r i p t i o n s and i n f o r m a t i o n sources f o r Oregon e s t u a r i e s . Sea Grant C o l l e g e Program, Oreg S t a t e Univ . , C o r v a l l i s . 294 pp.

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Reimers, P. 1974. The l e n g t h o f r e s i d e n c e o f j u v e n i l e f a l l ch inook salmon i n S i x e s R i v e r , Oregon. F i s h Comm. Oreg. Res. Rep. 4 ( 2 ) : 1 - 4 3 .

R i c k e t t s , E . and J . C a l v i n . 1968. Between P a c i f i c t i d e s . F o u r t h e d i t i o n , r e - v i s e d by J. W. Hedgpeth. S t a n f o r d Un iv . Press, S t a n f o r d , C a l i f . 614 pp.

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Smith, W . K lamath Mounta ins p r o v i n c e . 1940. Pp. 49-54 in Oregon S t a t e Board o f H i g h e r Educa t ion . P h y s i c a l and economic geography o f Oregon. 319 pp.

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Thayer, G . and R. P h i l l i p s . 1977. Impor tance o f e e l g r a s s beds i n Puget Sound. Mar ine F i s h e r i e s Review 39(11) :18-22.

~ h o r s o n , G . 1957. Bottom communit ies. Pp. 461-534 in Hedgpeth (ed . ) , T r e a t i s e on mar ine eco logy and pa leoeco logy , Vo l . 1 , GSA Memoir 67.

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Wi l sey and Ham. 1974. E s t u a r i n e resources o f t h e Oregon Coast . A n a t u r a l resource i n v e n t o r y r e p o r t t o t h e Oregon Coas ta l Conserva t ion and Development Commission. 233 pp.

Zegers, P. 1978. The e f f e c t s o f l o g r a f t g round ing on t h e b e n t h i c i n v e r t e b r a t e s o f t h e Coos e s t u a r y . Oreg. Dep. Env i ron . Q u a l i t y , Roseburg. Unpub.

Zieman, J . 1977. Sea g rass beds. Pp. 702-704 in C l a r k , Coas ta l ecosystem man- agement, a t e c h n i c a l manual f o r t h e c o n s e r v a t i o n o f c o a s t a l zone resources . The Conserva t ion Foundat ion. John W i l e y and Sons, New York . 928 pp.

Zimmerman, S . 1972. Seasonal success ion o f zoop lank ton p o p u l a t i o n s i n two d i s - s i m i l a r mar ine embayments on t h e Oregon c o a s t . Ph.D. Thes is , Oreg. S t a t e U n i v . , C o r v a l l i s .

Appendix A

OREGON ESTUARINE HABITAT CLASSIFICATION SYSTEM*

* M o d i f i e d f rom Cowardin e t a l . (1977) . E n t i r e s e c t i o n s o f t h e USFWS c l a s s i f i c a t i o n system were used i n t h e d e f i n i t i o n o f terms.

The p r e p a r a t i o n o f t h i s document was f i n a n c e d i n p a r t by funds f rom t h e Oregon Land Conserva t ion and Development Department and t h e O f f i c e o f Coasta l Zone Management, N a t i o n a l Oceanic and Atmos- p h e r i c A d m i n i s t r a t i o n , U.S. Department o f Commerce, and by t h e Oregon Department o f F i s h and W i l d l i f e . A d d i t i o n a l funds f o r comp le t ing t h e Oregon E s t u a r i n e H a b i t a t C l a s s i f i c a t i o n System were p rov ided by t h e N a t i o n a l Area Preserves A d v i s o r y Committee.

Shrub

- Cobble/gravel

Wood debris/organic

Shell

Mud

Sand-mud (mixed) + Bedrock

Cobble/gravel

Shell

Sand-mud (mixed) E .li Algal u o r iE 1 seagr...e.

Bedrock

Cobble/gravel

0 C n o c m

Sand-mud (mixed)

Sand

ESTUARINE SYSTEM

An e s t u a r i n e system has been d e f i n e d as "a semi-enclosed c o a s t a l body o f

wa te r ( i n c l u d i n g submerged land , t i d e l a n d , and t i d a l marsh) wh ich has a f r e e

connec t ion w i t h t h e open sea and w i t h i n wh ich sea w a t e r i s measurably d i l u t e d

w i t h f reshwate r d e r i v e d f r o m l a n d dra inage" ( P r i t c h a r d 1967). E s t u a r i e s

ex tend upstream t o t h e head o f t i d e w a t e r and landward t o t h e l i n e o f non-

a q u a t i c v e g e t a t i o n where marshes b o r d e r t h e e s t u a r y , o r t o mean h i g h e r h i g h

wa te r (MHHW) where t h e l i n e o f non-aqua t i c v e g e t a t i o n cannot be determined. '

The seaward l i m i t o f an e s t u a r y i s d e f i n e d by a l i n e ac ross t h e mouth o f t h e

e s t u a r y , a l t h o u g h e s t u a r i n e c o n d i t i o n s may ex tend seaward o f t h i s l i n e d u r i n g

p e r i o d s o f h i g h f r e s h w a t e r r u n o f f . The d i s t r i b u t i o n o f p l a n t s and an imals i n

t h e e s t u a r i n e system p r i m a r i l y r e f l e c t s d i f f e r e n c e s i n s a l i n i t y , s u b s t r a t e

compos i t i on , and e l e v a t i o n .

SUBSYSTEMS

Mar ine

The mar ine subsystem i s a h i g h energy zone l o c a t e d near t h e e s t u a r y

mouth. The bot tom i s i n f l u e n c e d by s t r o n g c u r r e n t s , and t h e s u b s t r a t e i s

p r i m a r i l y coarse mar ine sand, cobb le , and r o c k . S a l i n i t i e s a r e g e n e r a l l y h i g h

due t o t h e dominance o f ocean wa te r , b u t may be g r e a t l y reduced d u r i n g h i g h

r i v e r f l o w s i n w i n t e r . K e l p and o t h e r a l g a l spec ies o f t e n cover t h e rock

s u b s t r a t e s and fo rm mic rohab i t a t s f o r many spec ies (Markham 1967). B e n t h i c

i n v e r t e b r a t e s i n t h i s zone may i n c l u d e mar ine and e s t u a r i n e spec ies . Most

f i s h u t i l i z i n g t h i s subsystem a r e mar ine s p e c i e s .

Bay

The bay subsystem i s a r e l a t i v e l y p r o t e c t e d environment, o f t e n c h a r a c t e r -

i z e d by a broad embayment between t h e e s t u a r y mouth and nar row, u p r i v e r reaches

o f t i d e w a t e r . Norma l l y t h e bay subsystem has a l a r g e percentage o f i n t e r t i d a l

8 1

l a n d " Because i t i s a t r a n s i t i o n zone between mar ine and f r e s h w a t e r e n v i r o n -

ments, sediments o f t h e mar ine subsystem a r e p r i m a r i l y a m i x t u r e o f coarse ~ mar ine sands and f i n e r i v e r - b o r n e s i l t s and c l a y s . S a l i n i t i e s d u r i n g summer

a r e moderate t o h i g h depending on t h e s i z e o f t h e d ra inage , b u t may v a r y I

c o n s i d e r a b l y w i t h t i d a l s t a g e and f r e s h w a t e r f l o w . Most bays have a wide

d i v e r s i t y o f h a b i t a t s w i t h e x t e n s i v e i n t e r t i d a l f l a t s , e e l g r a s s beds, a l g a l

beds, and marshes.

Slough

The s lough subsystem i s a s h e l t e r e d env i ronment , wh ich i s u s u a l l y a

nar row, i s o l a t e d arm o f t h e e s t u a r y . Freshwater d r a i n a g e i n t o t h e s lough

subsystem i s e i t h e r low o r d i s p e r s e d by a number o f smal l c reeks , so t h a t t h e

c u r r e n t f l o w i n g th rough t h e s lough channel i s s low. The s a l i n i t y i s i n f l u e n c e d

by t h e p r o x i m i t y o f t h e s lough t o t h e e s t u a r y mouth. Sloughs u s u a l l y have f i n e

o r g a n i c sediments and h i g h percentages o f i n t e r t i d a l l and , c o n s i s t i n g o f

e x t e n s i v e f l a t s , e e l g r a s s beds and marshes.

R i v e r i n e

The r i v e r i n e subsystem i n c l u d e s t h e upper t i d e w a t e r p o r t i o n s o f t h e

l a r g e r t r i b u t a r i e s which e n t e r t h e e s t u a r y . A l a r g e percentage o f t h e sub-

system i s nar row, s u b t i d a l r i v e r channel . C u r r e n t v e l o c i t i e s e x h i b i t d r a m a t i c

seasonal changes which i n f l u e n c e b e n t h i c communit ies. S a l i n i t i e s a r e low most

o f t h e year , and p o r t i o n s o f t h e subsystem may be e n t i r e l y f r e s h wa te r .

Sediments range f rom f i n e s i l t s and c l a y s t o cobb le and g r a v e l . Small f r i n g i n g

marshes o c c u r on t h e nar row, i n t e r t i d a l p o r t i o n s o f t h e r i v e r bank.

TIDAL REGIME

S u b t i d a l

S u b t i d a l h a b i t a t s a r e below t h e extreme low wate r (ELM) t i d e l e v e l and

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have c o n t i n u o u s l y submerged s u b s t r a t e s .

l n t e r t i d a l

l n t e r t i d a l p o r t i o n s o f t h e e s t u a r i n e system a r e exposed and f l o o d e d by

t i d e s as f r e q u e n t l y as t w i c e d a i l y o r as i n f r e q u e n t l y as a few t imes a year .

I n t e r t i d a l h a b i t a t s a r e above ELW and i n c l u d e t i d a l marsh areas. The upper

l i m i t o f t h e i n t e r t i d a l zone i s d e f i n e d as t h e l i n e o f non-aqua t i c v e g e t a t i o n ,

o r as MHHW i n areas where t h e l i n e o f non-aqua t i c v e g e t a t i o n cannot be d e t e r -

SUBTIDAL CLASSES AND SUBCLASSES

Unconso l ida ted Bottom Class

T h i s c l a s s i n c l u d e s s u b t i d a l h a b i t a t s w i t h bot toms composed o f u n c o n s o l i -

da ted sediments t h a t a r e l e s s than 30% covered by v e g e t a t i o n . Coarse s u b s t r a t e s

a r e u s u a l l y found i n t h e mar ine and r i v e r i n e subsystems, w h i l e f i n e m a t e r i a l

i s d e p o s i t e d i n s loughs and low energy p o r t i o n s o f t h e bay subsystems (Kulm

and Byrne 1966). Unconso l ida ted bot toms do n o t have l a r g e , s t a b l e su r faces

f o r p l a n t and an imal a t tachment . They a r e found i n h i g h and low energy regimes

and may be v e r y u n s t a b l e . Exposure t o wave and c u r r e n t a c t i o n , sediment s i z e ,

temperature , s a l i n i t y , and l i g h t p e n e t r a t i o n i n f l u e n c e t h e compos i t i on and

d i s t r i b u t i o n o f organisms. Consequent ly, p l a n t and animal communit ies occupy ing

c o n s o l i d a t e d bo t tom h a b i t a t s w i l l v a r y f rom t h e open ocean t o t h e upper end o f

t h e e s t u a r y . The m a j o r i t y o f an imals i n u n c o n s o l i d a t e d sediments l i v e w i t h i n

t h e s u b s t r a t e . Some an ima ls , such as c e r t a i n po lychae tes , m a i n t a i n permanent

burrows, and o t h e r an ima ls may l i v e on t h e su r face , e s p e c i a l l y i n coarse

sed iments .

subc lasses o f u n c o n s o l i d a t e d bot tom

(1) Sand. The s u b s t r a t e i s p r i m a r i l y sand (75% o r more o f t h e sediment i s

0.0625-1 mm i n d iamete r ) i n t h e Wentworth sediment c l a s s i f i c a t i o n system),

a l t h o u g h f i n e r o r c o a r s e r sediments may be i n t e r m i x e d . The sand bot tom

has a l e s s d i v e r s e fauna and f l o r a than e i t h e r mud, mixed sand-mud, o r

cobb le /g rave l bot toms.

( 2 ) Sand-mud mixed. The s u b s t r a t e i s a m i x t u r e o f sand and mud. These

h a b i t a t s a r e t y p i c a l l y h i g h e r i n o r g a n i c c o n t e n t than sand and a r e f i r m e r

and more a e r a t e d than mud.

(3) Mud. The s u b s t r a t e i s p r i m a r i l y s i l t and c l a y (75% o r more o f t h e sediment

i s l e s s than 0.625 mm i n d i a m e t e r ) , a l t h o u g h c o a r s e r sediments and o r g a n i c

m a t e r i a l may be i n t e r m i x e d . Organisms l i v i n g i n mud must o f t e n t o l e r a t e

low oxygen c o n c e n t r a t i o n s .

(4) S h e l l . The s u r f a c e o f t h e s u b s t r a t e i s a t l e a s t 75% s h e l l .

S u b t i d a l s h e l l bot toms may be covered w i t h a l a y e r o f s h e l l severa l

c e n t i m e t e r s t h i c k .

(5) Wood d e b r i s / o r g a n i c . Subs t ra tes composed o f p r i m a r i l y wood d e b r i s and

o t h e r o r g a n i c m a t e r i a l u s u a l l y occur where c u r r e n t v e l o c i t i e s a r e low,

and/or t h e r e i s a s teady supp ly o f a d d i t i o n a l o r g a n i c m a t e r i a l .

(6) Cobb le /g rave l . The s u b s t r a t e i s p r i m a r i l y cobb le and g r a v e l

( f ragments l e s s than 256 mm, b u t g r e a t e r than 1 mm i n d i a m e t e r ) , a l t h o u g h

f i n e r sediments may be i n t e r m i x e d .

Rock Bottom Class

T h i s c l a s s i n c l u d e s s u b t i d a l h a b i t a t s w i t h r o c k s u b s t r a t e s t h a t a r e l e s s

than 30% covered w i t h v e g e t a t i o n . I t i s u s u a l l y a h i g h energy h a b i t a t w i t h

w e l l ae ra ted wa te rs . The f i r m s u b s t r a t e i s a p r i m a r y f a c t o r d e t e r m i n i n g

abundance, compos i t i on , and d i s t r i b u t i o n o f organisms. Temperature, s a l i n i t y ,

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c u r r e n t , and l i g h t p e n e t r a t i o n a r e o t h e r i m p o r t a n t f a c t o r s a f f e c t i n g t h e

compos i t i on o f t h e b e n t h i c community. Animals a r e g e n e r a l l y f i r m l y a t t a c h e d

t o t h e rocky s u r f a c e by hook ing o r s u c k i n g dev ices . Some spec ies move about

o v e r t h e s u b s t r a t e i n search o f food, w h i l e o t h e r s a r e permanent ly a t t a c h e d t o

t h e r o c k s u r f a c e . A few an ima ls h i d e i n rocky c r e v i c e s and under rocks, and

o t h e r s bur row i n t o f i n e r s u b s t r a t e s between b o u l d e r s . P l a n t s a r e f i r m l y

a t t a c h e d . Most r o c k bot toms o c c u r i n t h e mar ine subsystem.

Subclasses o f r o c k bo t tom

( I ) Bou lder . The s u b s t r a t e c o n s i s t s o f r o c k f ragments l a r g e r than 256 mm i n

d iamete r . O f t e n f i n e r m a t e r i a l i s mixed w i t h t h e l a r g e r f ragments.

(2) Bedrock. The s u b s t r a t e c o n s i s t s p r i m a r i l y o f bedrock s u r f a c e s . Unconso l i -

da ted sediments may s e a s o n a l l y cover p o r t i o n s o f t h e rock s u r f a c e s .

P iddock clams may burrow i n t o s o f t sed imentary rock ( R i c k e t t s and C a l v i n

1968) .

I A q u a t i c Bed Class

T h i s c l a s s i n c l u d e s s u b t i d a l h a b i t a t s w i t h s u b s t r a t e s t h a t a r e a t l e a s t

30% covered by submergent p l a n t s f o r t h e m a j o r i t y o f t h e growing season. The

p l a n t s g r e a t l y i n f l u e n c e t h e compos i t i on o f t h e r e s i d e n t an imal spec ies .

Subclasses o f a q u a t i c beds

(1) Seagrass. S u b t i d a l seagrass beds a r e composed p r i m a r i l y o f v a s c u l a r

a q u a t i c seed p l a n t s , p r i n c i p a l l y e e l g r a s s ( z o s t e r a m a r i n a ) . Ee lg rass

leaves suppor t many e p i p h y t e s which a r e consumed by f i s h and l a r g e r

i n v e r t e b r a t e s (Thayer and Phi 1 1 i p s 1 9 7 7 ) Ee lg rass beds reduce c u r r e n t s

and promote sediment d e p o s i t i o n .

(2) A l g a l . S u b t i d a l a l g a l beds c o n s i s t o f macroalgae a t t a c h e d t o rock sub-

s t r a t e s and u n c o n s o l i d a t e d s u b s t r a t e s . Genera common i n Oregon e s t u a r i e s

8 5

i n c l u d e Enteromorgha, Ulva, and Fucus spp. Beds o f k e l p w i t h h o l d f a s t s

( o r d e r ~ a m i n a r i a l e s ) occur i n t h e mar ine subsystem near t h e mouths o f

some e s t u a r i e s and c o n t a i n many i n v e r t e b r a t e s arkha ham 1967) . Many

macroalgae a t t a c h t o u n c o n s o l i d a t e d s u b s t r a t e s by means o f a basa l h o l d f a s t

o r d i s c . However, i n sand and mud, a l g a e p e n e t r a t e t h e s u b s t r a t e , and

h i g h e r p l a n t s can s u c c e s s f u l l y r o o t i f wave a c t i o n and c u r r e n t s a r e n o t I

t o o s t r o n g .

INTERTIDAL CLASSES AND SUBCLASSES I

Shore Class

T h i s c l a s s i n c l u d e s i n t e r t i d a l h a b i t a t s w i t h r o c k o r u n c o n s o l i d a t e d

s u b s t r a t e s o c c u r r i n g as a nar row band between up lands ( o r t i d a l marshes) and a

s u b t i d a l wa te r course. Shores a r e g e n e r a l l y h i g h energy h a b i t a t s which a r e

exposed t o s t r o n g waves and t i d a l and r i v e r c u r r e n t s . Shores a r e u s u a l l y

unvegetated because o f t h e s c o u r i n g e f f e c t o f t h e c u r r e n t s b u t may have f r i n g i n g

marshes and seasonal a l g a l cover . I n shore h a b i t a t s w i t h u n c o n s o l i d a t e d

s u b s t r a t e s , s c a t t e r e d p e r e n n i a l ernergents and shrubs may o c c u r b u t n o t i n

s u f f i c i e n t d e n s i t y ( l e s s than 30% c o v e r ) t o c l a s s i f y t h e a rea as t i d a l marsh.

On rocky shores t h e s u b s t r a t e i s s t a b l e enough t o p e r m i t t h e a t tachment and

growth o f s e s s i l e o r sedentary i n v e r t e b r a t e s , a l g a e , and l i c h e n s . Shores

u s u a l l y d i s p l a y v e r t i c a l z o n a t i o n , wh ich i s a f u n c t i o n o f t i d a l range, r i v e r

f l o w , wave a c t i o n , and degree o f exposure.

Subclasses o f shores

(1) - Sand. The s u b s t r a t e i s p r i m a r i l y sand (75% o r more o f t h e sediment i s

0.0625-1 mm i n d i a m e t e r ) , wh ich o c c a s i o n a l l y may be scoured by s to rm

waves o r f l o o d c u r r e n t s t o expose b o u l d e r s o r bedrock.

;1 (2) Sand-mud mixed. The s u b s t r a t e c o n s i s t s o f mixed sand and mud. The mud

may be removed f rom shores s u b j e c t t o s e a s o n a l l y v a r y i n g wa te r v e l o c i t i e s

d u r i n g h i g h f l o w s , o r t h e e n t i r e s u b s t r a t e may be p e r i o d i c a l l y swept

away. I

I ( 3 ) Mud, The s u b s t r a t e i s p r i m a r i l y s i l t and c l a y (75% o r more o f t h e sediment

I i s l e s s than 0.0625 mm i n d i a m e t e r ) . The s u b s t r a t e o f shores s u b j e c t t o

I s e a s o n a l l y v a r y i n g v e l o c i t i e s may change f rom mud t o sand-mud mixed. I I

(4) S h e l l . The s u r f a c e o f t h e s u b s t r a t e i s a t l e a s t 75% s h e l l f ragments.

1 Very few u n a l t e r e d areas would be c l a s s i f i e d as s h e l l shore, s i n c e s h e l l

I i s u s u a l l y a smal l f r a c t i o n o f t h e s u b s t r a t e compos i t i on i n i n t e r t i d a l

I a reas .

i (5 ) Wood d e b r i s / o r g a n i c . The s u b s t r a t e i s p redominan t l y wood d e b r i s and

I o t h e r o r g a n i c m a t e r i a l . Scour ing may a l s o p e r i o d i c a l l y change t h e sub-

s t r a t e o f these shores.

(6) Cobb le /g rave l . The s u b s t r a t e i s p r i m a r i l y cobb le o r g r a v e l ( f ragments

l e s s than 256 mm b u t g r e a t e r than 1 mm i n d iamete r ) o f t e n c a r r i e d down-

i s t ream w i t h h i g h w i n t e r f l o w s , d e p o s i t e d on t h e e s t u a r y shore a t t h e

mouths o f smal l s teep c reeks , o r f ragmented f rom e s t u a r i n e headlands and

i s l a n d s .

(7 ) Bou lder . The s u b s t r a t e c o n s i s t s p r i m a r i l y o f r o c k f ragments l a r g e r than

i 256 mm i n d iamete r . O f t e n f i n e r m a t e r i a l i s mixed w i t h t h e l a r g e r f ragments .

(8) Bedrock. The s u b s t r a t e c o n s i s t s p r i m a r i l y o f bedrock s u r f a c e s . Unconsol-

i d a t e d sediments may s e a s o n a l l y cover p o r t i o n s o f t h e rock s u r f a c e s .

F l a t C lass

T h i s c l a s s i n c l u d e s i n t e r t i d a l landforms w i t h a g radua l s lope , which

n o r m a l l y o c c u r i n areas s h e l t e r e d f r o m s t r o n g c u r r e n t s and wave a c t i o n

Shapes and l o c a t i o n s o f f l a t s v a r y , b u t most f l a t s occur i n t h e bay and s lough

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subsystems. F l a t s a r e broader , more g radua l i n s lope , and s u b j e c t t o s lower

c u r r e n t than a d j a c e n t shores. T h i s c l a s s i n c l u d e s vege ta ted f l a t s l e s s than

30% covered by p l a n t s d u r i n g t h e summer. More dense ly vege ta ted f l a t s a r e

c l a s s i f i e d as a q u a t i c beds o r t i d a l marshes.

Community s t r u c t u r e i s i n f l u e n c e d by sediment c h a r a c t e r i s t i c s , c u r r e n t s ,

wave a c t i o n , temperature , and s a l i n i t y . R e g u l a r l y f l o o d e d f l a t s suppor t

d i v e r s e p o p u l a t i o n s o f t u b e - d w e l l i n g and b u r r o w i n g i n v e r t e b r a t e s i n c l u d i n g

worms, c lams, and crustaceans. These i n v e r t e b r a t e s a r e p r i m a r i l y d e t r i t u s

f e e d e r s . F l a t s a l s o a r e commonly c o l o n i z e d by macroalgae, d ia toms, and sea-

grasses. Animals and p l a n t s have adapted t o t h e w ide ranges o f temperature

and s a l i n i t y c h a r a c t e r i s t i c o f f l a t s . A f l a t may be r e l a t i v e l y s t a b l e , o r may

i n c r e a s e I n t o t a l a rea , e l e v a t i o n , o r percentage o f v e g e t a t i v e cover . F l a t s

seldom decrease i n e l e v a t i o n o r s i z e under n a t u r a l c o n d i t i o n s .

Subclasses o f f l a t

(1) Sand. The s u b s t r a t e i s composed p r i m a r i l y o f sand (75% o r more o f t h e - sediment i s 0.0625-1 mm i n d iamete r ) , o f t e n w i t h p a r t i c l e s o f o t h e r s i z e s

i n t e r m i x e d . A l though p o p u l a t i o n d e n s i t i e s may be v e r y h i g h , spec ies

d i v e r s i t y i s o f t e n low.

(2) Sand-mud mixed. The s u b s t r a t e i s a m i x t u r e o f sand and mud. Sand-mud

f l a t s a r e t y p i c a l l y h i g h e r i n o r g a n i c c o n t e n t than sand f l a t s and a r e

f i r m e r and more a e r a t e d than mud f l a t s .

(3 ) Mud. The s u b s t r a t e i s p r i m a r i l y s i I t and c l a y (75% o r more o f t h e sediment

i s l e s s than 0.0625 mm i n d iamete r ) and i s o f t e n anaerob ic below t h e

s u r f a c e . Organic c o n t e n t i s g e n e r a l l y h i g h e r than i n t h e o t h e r subclasses

o f f l a t s (except wood d e b r i s / o r g a n i c ) .

(4) She1 I . The s u b s t r a t e i s a t l e a s t 75% she1 I. T h i s t y p e o f f l a t i s n o t

common under n a t u r a l c o n d i t i o n s .

8 8

(5 ) Wood d e b r i s / o r g a n i c . The s u b s t r a t e i s p r i m a r i l y wa te r logged wood d e b r i s ,

p e a t , and o t h e r o r g a n i c m a t e r i a l .

(6) Cobb le /g rave l . T h i s s u b s t r a t e c o n s i s t s p r i m a r i l y o f cobbles o r g r a v e l

( f ragments l e s s than 256 mm b u t g r e a t e r than 1 mm i n d i a m e t e r ) , o f t e n

w i t h s h e l l f ragments o r f i n e r sediments i n t e r m i x e d

A q u a t i c Bed Class

T h i s c l a s s i n c l u d e s m a i n l y l ower i n t e r t i d a l h a b i t a t s w i t h a t l e a s t a 30%

v e g e t a t i v e cover d u r i n g t h e m a j o r i t y o f t h e g row ing season. As i n t h e sub-

t i d a l a q u a t i c bed c l a s s , two subc lasses o f p l a n t s a r e dominant i n t h e com-

p o s i t i o n o f t h e r e s i d e n t community.

Subclasses o f a q u a t i c beds

( I ) Seagrass. I n t e r t i d a l seagrass beds a r e composed p r i m a r i l y o f v a s c u l a r

a q u a t i c seed p l a n t s , such as e e l g r a s s ( z o s t e r a marina, z. nana) .

(2) A l g a l . I n t e r t i d a l a l g a l beds c o n s i s t o f macroalgae a t t a c h e d t o rock and

u n c o n s o l i d a t e d s u b s t r a t e s . Genera common i n Oregon e s t u a r i e s i n c l u d e

Enteromorpha, Ulva, and F u c u s spp.

Beach/Bar Class

T h i s c l a s s i n c l u d e s s l o p i n g i n t e r t i d a i landforms c r e a t e d by waves and

c u r r e n t s , wh ich a r e composed p r i m a r i l y o f u n c o n s o l i d a t e d sand, g r a v e l , o r

cobbles. These h i g h energy h a b i t a t s have l e s s than 30% v e g e t a t i v e cover .

Beaches a r e l i m i t e d t o a reas i n t h e mar ine subsystem i n f l u e n c e d by ocean waves

and cu r ren t ' s , and extend landward t o a d i s t i n c t break i n land fo rm o r s u b s t r a t e

t y p e (e .g . , a foredune, c l i f f , o r bank) o r t o t h e p o i n t where v e g e t a t i o n

covers 30% o r more o f t h e s u b s t r a t e . Bars a r e e l o n g a t e r i d g e s , banks, o r

mounds w i t h wa te r on a t l e a s t two s i d e s . Bars most o f t e n o c c u r i n t h e mar ine

and r i v e r i n e subsystems. Bars may o n l y be i r r e g u l a r l y o r s e a s o n a l l y f looded.

~ ~ ~ c h e ~ and b a r s a r e c h a r a c t e r i z e d by a s h i f t i n g , u n s t a b l e s u b s t r a t e w i t h h i g h

p e r m e a b i l i t y , v a r i a b l e s u r f a c e m o i s t u r e , and low percen tage o f o r g a n i c m a t t e r .

The s u r f a c e l a y e r has a h i g h oxygen c o n t e n t , b u t t h e r e i s o f t e n a deeper

a n a e r o b i c l a y e r . Beaches and b a r s may be s p a r s e l y vege ta ted and a r e popu la ted

by s p e c i a l i z e d bur row ing i n v e r t e b r a t e s , such as m o l l u s c s , c rus taceans , and

po lychae tes . Faunal d i s t r i b u t i o n i s i n f l u e n c e d by waves, c u r r e n t s , i n t e r s t i t i a l

m o i s t u r e , s a l i n i t y , and sediment g r a i n s i z e .

Subclasses o f beach/bar

(1) The s u b s t r a t e i s p r i m a r i l y sand (75% o r more o f t h e s u b s t r a t e i s

0.0625-1 mm i n d i a m e t e r ) . Cobble o r g r a v e l may be i n t e r m i x e d .

(2 ) Cob Cobble and g r a v e l ( f ragments l e s s than 256 mm b u t g r e a t e r

than 1 mm i n d iamete r ) dominate t h e s u b s t r a t e , a l t h o u g h sand i s u s u a l l y

mixed w i t h these l a r g e r p a r t i c l e s . Some o f t h e l a r g e r cobb les and

occas iona l b o u l d e r s found i n these areas may s u p p o r t s e s s i l e organisms.

Cobble /grave l beaches and bars t y p i c a l l y fo rm where wave a c t i o n o r c u r r e n t s

a r e p a r t i c u l a r l y s t rong . As a r e s u l t , sand and s i l t p a r t i c l e s may be

eroded and t r a n s p o r t e d f r o m t h e beach o r b a r and d e p o s i t e d i n deeper

wa te rs .

T i d a l Marsh Class

T h i s c l a s s i n c l u d e s h i g h e r i n t e r t i d a l landforms t h a t a r e more than 30%

covered by e r e c t , r o o t e d herbaceous, o r woody hydrophytes. The t i d a l marsh

g e n e r a l l y occurs f rom s l i g h t l y below mean h i g h wa te r (MHW) i n l a n d t o t h e l i n e

o f nonaqua t i c v e g e t a t i o n . Community compos i t i on v a r i e s p r i m a r i l y w i t h t i d a l

e l e v a t i o n b u t i s a l s o i n f l u e n c e d by sediment t y p e and s a l i n i t y . P l a n t producers

i n s a l t marshes i n c l u d e n o t o n l y marsh grasses b u t a l s o macroalgae entwined

among t h e g rass stems, m i c r o a l g a e on t h e mud s u r f a c e , and p h y t o p l a n k t o n i n t h e

wa te r column. Organic m a t e r i a l and n u t r i e n t s s t o r e d by marsh producers a r e

90

~ ~

consumed d i r e c t l y o r t r a n s p o r t e d t o o t h e r p o r t i o n s o f t h e e s t u a r y as d e t r i t u s .

Marshes p r o v i d e h a b i t a t f o r f i s h , i n v e r t e b r a t e s , w a t e r f o w l , and sma l l t e r r e s -

t r i a l mammals. A d i v e r s i t y o f i n s e c t s l i v e among and g raze on marsh grasses.

Subclasses o f t i d a l marsh

( I ) Low s a l t marsh. Low s a l t marshes a r e e n t i r e l y f l o o d e d by most h i g h t i d e s ,

and, t h e r e f o r e , c o n t r i b u t e t o t h e e s t u a r i n e food s u p p l y on a d a i l y b a s i s .

T i d a l r u n o f f i s g e n e r a l l y d i f f u s e r a t h e r than c o n t a i n e d by deep d i t c h e s .

The marsh s u r f a c e i s g e n e r a l l y f l a t b u t s lopes s l i g h t l y upward toward

l a n d . Depending on t h e s u b s t r a t e a c o l o n i z i n g marsh community near mean

h i g h wa te r i s comprised o f seas ide a r r o w g r a s s ( T r i g l o c h i n m a r i t i m a ) ,

seacoast b u l l rush ( s c i r p u s m a r i t i m u s ) , o r Lyngbye 's sedge ( c a r e x l y n g b y e i )

(F renke l and E i l e r s 1976). T h i s lower i n t e r t i d a l marsh f r e q u e n t l y shows

h i g h spec ies dominance and low d i v e r s i t y ( E i l e r s 1975).

( 2 ) High s a l t marsh. - High s a l t marshes u s u a l l y r i s e a b r u p t l y 0.3 t o 1 m

above t h e a d j a c e n t f l a t , shore, o r low marsh ( J e f f e r s o n 1975). The marsh

I s u r f a c e i s i r r e g u l a r w i t h g e n e r a l l y con t inuous p l a n t cover i n t e r s p e r s e d

w i t h p o t h o l e s , s a l t pans, and channels . The marsh s u r f a c e i s covered by

most h i g h e r h i g h t i d e s and t i d a l r u n o f f f o l l o w s w e l l d e f i n e d channels

w i t h n a t u r a l l evees . D i v e r s i t y i s u s u a l l y g r e a t e r i n h i g h marsh communit ies

than i n low marshes. T y p i c a l h i g h marsh and t r a n s i t i o n zone spec ies a r e

d e s c r i b e d by F renke l e t a l . (1978) .

(3 ) Fresh marsh. Fresh marshes o c c u r i n l a n d o f s a l t marshes where s o i l

s a l i n i t y i s l ow o r i n t h e upstream p o r t i o n o f t h e e s t u a r y where f r e s h

wa te r under t i d a l i n f l u e n c e p e r i o d i c a l l y inundates t h e marsh. Vege ta t ion

i s herbaceous w i t h sedge ( c a r e x s p . ) , b u l l r u s h ( s c i r p u s s p . ) , and c a t t a i 1s

(Typha sp.) u s u a l l y dominant (Ak ins and J e f f e r s o n 1973) .

(4) Shrub. Shrub wet lands may o c c u r a t t h e i n l a n d boundary o f t h e e s t u a r y .

I n Oregon, w i l l o w ( s a l i x sp.) i s t h e p r i m a r y semi -aqua t i c woody p l a n t

t h a t i s l i k e l y t o occur . W i l l o w , however, has a low s a l i n i t y t o l e r a n c e

and, t h e r e f o r e , i s most o f t e n found i n t h e r i v e r i n e subsystem.

MODIFIERS

Severa l m o d i f i e r s o f t h i s h a b i t a t c l a s s i f i c a t i o n system h e l p t o more

a c c u r a t e l y c h a r a c t e r i z e e s t u a r i n e h a b i t a t s . These m o d i f i e r s may be a p p l i e d t o

any l e v e l o f t h e c l a s s i f i c a t i o n system.

T i d e Leve l and S a l i n i t y

T i d a l e l e v a t i o n and s a l i n i t y regime a r e t h e p r i m a r y p h y s i c a l f a c t o r s

i n f l u e n c i n g community c o m p o s i t i o n i n an e s t u a r y . A marked v e r t i c a l and l o n g i -

t u d i n a l z o n a t i o n o f spec ies occurs i n e s t u a r i e s due t o changes i n t i d a l l e v e l

and s a l i n i t y . I n t e r t i d a l spec ies e x h i b i t s p e c i a l a d a p t a t i o n s t o r e s i s t

d e s s i c a t i o n , t o t o l e r a t e l a r g e v a r i a t i o n s i n tempera tu re due t o t i d a l exposure,

and t o r e g u l a t e i n t e r n a l s a l i n i t y . For a b road l e v e l h a b i t a t d e s c r i p t i o n ,

s u i t a b l e m o d i f i e r s i n c l u d e t h e genera l c a t e g o r i e s used by Cowardin e t a l .

(1977) ( i r r e g u l a r l y exposed, r e g u l a r l y Flooded, i r r e g u l a r l y f l o o d e d ) and t h e

subsystem c a t e g o r i e s d e s c r i b e d p r e v i o u s l y (mar ine, bay, s lough , r i v e r i n e ) .

For more s p e c i f i c h a b i t a t c h a r a c t e r i z a t i o n s , t i d a l l e v e l s and s a l i n i t y s h o u l d

be q u a n t i f i e d .

Spec ia l M o d i f i e r s

Some e s t u a r i n e h a b i t a t s have been m o d i f i e d by human a c t i v i t y . S ince these

m o d i f i c a t i o n s may g r e a t l y i n f l u e n c e t h e community compos i t i on , t h e f o l l o w i n g

m o d i f i e r s may be used t o d e s c r i b e such h a b i t a t s .

Excavated -- The excavated m o d i f i e r i s used t o d e s c r i b e e s t u a r i n e b a s i n s o r channels

wh ich r e c e i v e p e r i o d i c d redg ing . B e n t h i c i n v e r t e b r a t e and p l a n t communit ies

a r e k e p t a t a low l e v e l o f success ion by t h e p e r i o d i c removal o f t h e s u b s t r a t e

s u r f a c e .

I The d i k e d m o d i f i e r i s used t o d e s c r i b e h a b i t a t s ( u s u a l l y marsh) i n wh ich

t h e n a t u r a l f l u s h i n g i s s e v e r e l y r e s t r i c t e d by d i k e s o r b a r r i e r s . Some areas

t h a t a r e p a r t i a l l y d i k e d o r have open c u l v e r t s o r t i d e g a t e s may p e r m i t reduced

exchange o f wa te r between t h e d i k e d area and main body o f t h e e s t u a r y . O f t e n

I t hese areas have l a r g e a l g a l blooms, low oxygen c o n c e n t r a t i o n s , and e x h i b i t

d i f f e r e n t f l o r i s t i c c h a r a c t e r i s t i c s than s i m i l a r und iked a reas .

A r t i f i c i a l

I The a r t i f i c i a l m o d i f i e r r e f e r s t o e s t u a r i n e s u b s t r a t e s r e s u l t i n g f rom

man-made a l t e r a t i o n s . J e t t i e s , breakwaters , r i p r a p , a r t i f i c i a l r e e f s , docks,

p i e r s , and p i l i n g s a r e examples o f a r t i f i c i a l h a b i t a t s . Dredge s p o i l and l o g

s t o r a g e areas a r e a l s o i n c l u d e d i n t h e a r t i f i c i a l ca tegory .

LITERATURE CITED

Ak ins, G. J . and C . A. J e f f e r s o n . 1973. Coasta l we t lands o f Oregon. Oreg. Coas ta l Conser. Oev. Comm. F lo rence . 190 pp.

Cowardin, L . M., V . C a r t e r , F . C . G o l e t , E. T . LaRoe. 1977. C l a s s i f i c a t i o n o f we t lands and deep-water h a b i t a t s o f t h e U n i t e d S t a t e s . (An o p e r a t i o n a l d r a f t ) (Sa ther , J. t i . , e d ) . U.S. F i s h W i l d l . S e r v i c e , Wash., D.C.

E i l e r s , H . P. 1975. P l a n t s , p l a n t communit ies, n e t p r o d u c t i o n and t i d e l e v e l s : t h e e c o l o g i c a l b iogeography o f t h e Nehalem s a l t marshes, T i l l a m o o k County, Oregon. Ph.0. Thes is , Oreg. S t a t e Un iv . , C o r v a l l i s .

F r e n k e l , R. E . and H. P. E i l e r s . 1976. T i d a l datums and c h a r a c t e r i s t i c s o f t h e upper l i m i t s o f c o a s t a l marshes i n s e l e c t e d Oregon e s t u a r i e s . A p i l o t s t u d y conducted f o r t h e Env i ronmenta l P r o t e c t i o n Agency. Dept. o f Geogr., Oreg. S t a t e Univ . , C o r v a l l i s . 320 pp.

F renke l , R. E. , T. Boss, S . R. S c h u l l e r . 1978. T r a n s i t i o n zone v e g e t a t i o n between i n t e r t i d a l marsh and up land i n Oregon and l l a s h i n g t o n . Oept. o f Geogr., Oreg. S t a t e Un iv . , C o r v a l l i s . 320 pp.

J e f f e r s o n , C . A. 1975. P l a n t communit ies and success ion i n Oregon s a l t marshes. Ph.D. Thes is , Oreg. S t a t e U n i v . , C o r v a l l i s . 192 pp.

Kulm, L. D. and J. V . Byrne. 1966. Sedimentary response t o hydrography i n an Oregon e s t u a r y . Mar ine Geology 4:85-118.

Markham, J . C . 1967. A s tudy o f t h e an imals i n h a b i t i n g l a m i n a r i a n h o l d f a s t s i n Yaquina Bay, Oregon. M . S . Thes is , Oreg. S t a t e Un iv . , C o r v a l l i s , O r . 62 PP.

P r i t c h a r d , D. W . 1967. What i s an e s t u a r y : P h y s i c a l v i e w p o i n t . Pp. 3-5 H. L a u f f (ed.) , E s t u a r i e s . Pub. No. 83, American A s s o c i a t i o n f o r t h e

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m * u - * * :: 4 m w

appendix able 8. (continued)

2. T ida l wave

e s t u a ~ y inc luding Is9 timr, ampii- f i c a f i o n and choking, and v e l o s l t l e r ( m e Y6 below)

L w a f i o n o f h igh cnargy environments I" the estuary.

ure o f the Data

To determine i n f e r f i d a l / r u b t i d a i boundary a s de- fined by LCOC Estuar ine Rerourcer Goal.

To d i f f e r c n l i a f e I n t e r t i d a l and r u b t i d a l h a b i t a t s as defined by the Oregon Estuar ine Habi tat C l a r r i - f l c a f i o n System. To i d e n t i f y '%etlflandr" ar dc- f ined by LCOC Estuar ine Resovises Goal.

To determine i n t e r r i d a l l u p l a n d boundary as def ined by LCOC Estuar ine Rerourser Goal and cha Oregon Estuar ine Habi tat C l a r r i f i c a f i o n S y ~ f e m .

To determine i n t e i t i d a l l u p l a n d boundary where l i n e o f nonaquaflc vegetat ion i s nor appl icable ar de- f i ned by LCDC Estuar ine Resources Goal and the Oregon Estuar ine H a b i t a t C l a r r i f i c a l i o n Syrfen.

To determine the e f f e c t s o f the t i d e on estuar ine c i r c u l a t i o n . To determine loca l t i d a l va r ia t ions due t o topographic feafvrer o f the estuary. TO determine predominant type o f t i d a l wave (pro- g re r r i ve , standing wave, or both) .

TO i d e n t i f y p o t e n t i a l l y "n r tab ls and sroriv. a r e a s . To determine the inf luence of o r i e n t a t i o n to wind and waver on the d l r t r i b v r i o n o f organirnr i n thc estuary.

Suggested nerhodr/Data Sources

Draw ULLW datum on 1:12.000 base map. Esfilnafe MLLY frm f i e l d survey a t r e l e s i s d r t a i i o n r throughout the egrvary dur ing p red ic ted MLLW t i d a l levels. V e r i f y actual t i d e l c v e l r dur ing the survey frm ncarert ava i lab le recording r i d e gauge and nulie necessary cor res t ion r . Appropr iate m t h o d r ava i lab le f r m DSL, Salem. l la f ional Ocean Survey chart5 record soundlngr f o r m r l a rger estuar ies i n r e l a t i o n to the MLLU l e v e l .

A ~ p r o x i n v i i o n r for 1:12.000 planninq bare can be made frm a e r i a l photor and/or f i e l d surveys dur ing appropr iate r p r i n g lar r i d e r . Ex t rapo la t ion o f ELW datum a lso sao be lnade f r a n survey t o derermine nLLw (see # I b above). A p p r ~ p r i a f e "efhodr ava i lab le fro" DSL, sate..

Crude e s t i m f e r f ran a e r i a l photo3 and f i e l d v e r i f i c a t i o n f o r approXilMfion a t 1:12,000 scale p lanning bare. @,re accurate method3 required for imp iewnfa f inn o f p lans and lega l pur- poser. Frenkel. ef a t . (1978) o u t l i n e appropr iate nxrhadr f o r "are accurate ly determining t r a n r i t i o n zone fro. i n t e r -

See nethodr Ulb above f o r e r t i n v r l n g l i n e o f MLLv. Appro- p r i a t e m f h o d ~ a v a i l a b l e f ra DSL, Salem.

Select l oca t ion r f r m nourh ro upper t idewater for t i d a l gauge and current m r u r e n e n t r . sampling rhov id cover c m p l e t e t i d a l syc le r (lower la* to higher h igh t ides ) . Ar a minimum, rfudie. should be conducted for la f la* con- d i f i o n r f o r both sp r ing and neap f i d e r . Ders r lp t ion o f standing and progresr ive wave c h a r a c r e r i r f i c r g iven i n Dyer (1973).

Searon.1 obrervafionr o f WM helghf and dlr.srlon lns lud lng average and extrenr wind condi t ions.

Appendix Table 8. (conflnued)

4. River Discharge

Ure o f the Data Suggested HethodrIDafa Source

Averaae m n r h l r and e x t r e k f lows [above hoad o f t i d e ) for -jar t r l b u t a r l o s o f the estuary (current and h l r f o r -

TO d e f ~ r n i n e v o l v m r o f fre9h water en te r ing the e r tuary by source. To defernine the in f luence o f the,. r o u r s ~ l on f lush ing f l n a r , r a l i n l f y d i r t r l - but ion. mix ing c h a i a c f e r l r f i c r , and rpec ic r d i s t r i b u t i o n .

Requires stream gauger on the mjor f r i b f u a r l r r o f each estuary. Data ava i lab le I n nany areas from USGS (e.9. 1977) oats r m r i z e d f o r nany es tuar ies i n Percy ct a t . (1977). DSWRB ( 1 9 7 4 ) ~ and the OSWRB b a r i n reports (e.9. 1961). an dm v a l l x n f o r sone snmller t r l b v r a r i e r i n Oregon Gcnr C m i r r i a n Environnrnta l l n v e ~ f i ~ a f i o n r repor ts (c.9. Smith and Laumn 1972) and Oregon F i s h C o m i r r i o n stream surveys

*5. Flushing

E r t i m f e d f lushing To p red ic t the m v e e n f and f l u s h i n g o f introduced ~ v a l ~ a t e f l u s h i n g fine f o r loca t ions fmm lower t o upper t l n . 9 for r c i c f t e d po l iu ranrs f o r selected l o ~ a t l o n ~ f o r varying flar estuary f o r h igh and la flar condi t ions. T ida l p r l r l n

estuary l o c a t l ~ n r and t i d a l reg lms . TO i d e n t i f y arsar of high p o i l u - refhod f o r ca lcu la r ing f l u s h i n g tilnr (Dyer 1973) can be i n s l d l n g mjor f i o n p o t e n t i a l "red. s l o t t a and noble (1977) d iscur r lnrhodn f o r deter- f r i b u t a r l e s (see mining f l v r h l n g r i m 3 for nar ina r i n Oregon eafuar ier .

Y6 b e l a ) ~ i d a l p r i m s a l c u l a r i o n r described i n Goodwin ef a l . (1970) and cianznan er a i . (1971). uye and current study n r thodr for dessr ibtng f l u s h i n g s h a r e c f e r i r i i s s d iscusred i n G lan lmn ef a i . (1971).

" l x lng cl.rr1fi- ~ a f l o n under rearonal f l a condi t ions (see "WATER QUALITY-

s.11nity)

7. c i r c u l a t i o n

cu r ren t parterns and v e l o c i f l e l for selected lo6.tims a t vsry ing f l a r s g i n r r

To evaluate the inf luence o f n i x i n g on the d i r t r i - but ion. f ranrmrt . and concentrat ion o f m l l v t a n t s or oth;r nate;ial; i n the er tuary. To e"al"afe the lnf iuence o f reasons1 mix ing c h a r a c t ~ r l r f l c r an the c m p o r l t i ~ n and d i r t r i b u t l o n o f species i n the er tuary.

To determine loca l and rearonal v a r i a t i o n s i n

tween current oafterns and transport and d i a t r i - bu t ion o f r c d i n n r r Cree "Sedlnxnt"1, transport and d i r r r l b u r i o n of p o l l v t e n t r or o ther m t e r l a l r (see X2 above). salinity and n i x i n g pattsrnr (see #3 above). and the d l r f r l b v t i o n o f lankt tonic and

m y be w e d t o c l a i r i f y by n i x i n g type

ve loc i t y and d i r e c t i o n m n i t o r e d by current nrferr a t f i xed r t a r i o n r frm l w e r to upper e r fuary . Current nrarure- m n t s m d e a t surface and b o t t w far sw.wlefs t i d a l cycles ( lower lw to hleher h igh t i d e ) f a r h igh and la fla condi- t ions. Q u u l l t a t l v e Informat ion concerning current patterns can be obtaived by release and recapture of drmwr f r a n selected loca t loo r f ran 1-r to uomr estuary. Methods re- l a t i n g to estuar ine current merurenenfr d i r c u r r e d i n Clanmm=n ct a l . 11971).

i a r v o l form3 BI wel l as other rpcciea I n the estuary. (we Table 2 "BIOLOGICAL CHARACTERISTICS")

Appendix Table 8. (cont inuadl

Data Needs

I. SEDIMENTS

Use o f the Data Suggested Mcfhodr/Dafa Sovrser

I. k ~ r r f l o n and erosion

n i ~ f o r l c a l changer To d e t e r n i n ~ areas, degree. and p o t e n t i a l causer o f See "PHISICAL DiflEiISIOIIS-E3fu.r~ bare map, errvary shape, and i n i b r e l l n a conflg- a i o r i o n and r e d i m n t a t i o n . To i d e n t i f y p o t e n t i a l Boffm topographylwater depth". See "HYDROLOGICAL CHARACTER- u ra f lon and depth as res to ra t ion r i t e s o r measurer. ISTICS-Tidal wave and c i rcu la t ion" . S- h i s t o r i c a l data ~ l i as area3 o f a v a i l a b l e frm USACE nav iga t ion charts and U.S. Caarf and a ~ s r s f l o n and erosion. Gsodefic Survey Maps.

2. P a r t i c l e SIZE d l * - t r i b v t l o n

Sadlrmnt p a r t i c l e s i r e and d l r t r l - buflon o f p r e d m l - "ant g r a i n ,ires thmuohout fhc erfu-

Select core rampling r i t e s fa charac te r i ze redinenfs i n the major h a b i t a t types throughout r h e e r tuary . Larger g r a i n siz.3 (>.062 ml can be determined by ~ e i v e a n a l y r i r us ing 9tandard set o f Ty le r .elver lT*enhofel and Ty le r 19711. wh i le smaller f rac t ions requ i re p i p e t t e ana lys is or hydro- re fer . ~ e t e r m i n e n rd ian g r a i n r i r e r and percentages o f rand, s i l t , and c l a y f o r each sample. Map redineof d i s r r i - bu t ion on 1:12.000 scale bare m p . S m r q u a i i f a f i v e dafa for sediment d i s t r i b u t i o n ava i lab le frm a r o r i e r o f ODFU h a b i t a t maps k g . OOW 19781. s m data a v a i l a b l e frm USACE dredging records. Ana ly t i ca l nxrhodr and s t a t i s t i c a l t rea imntr dercr ibed i n Twenbfe l and T y l e r (19411 and Holme and l l c ln ty re (19711.

"3. Sedlmnf Q u a l i t y

Sedinent chemical TO arrerr potenr ia l t o x i c i t y o f sediments i n area3 parameters o f i n t e r e s t inc lude bu t not l i m i t e d to v o l a t i l e analyses where dredge selected f o r dredge or in-water d i i p o r a l o f dredged r o l i d s , chemical oxygen demand, t o t a l KJcldahl n i t rogen . and f i l l operat ions are mater ia l . For dredged mafa r ia l d i rpo ra l planning. o i l and grease, mercury, lead. z inc . U. S. Environmental considered Pro tec t ion Agency (LPA) standards and a n a l y t i c a l m f h o d r f o r

sediment analvrer dercr ibed i n O'Heil and Sceva (1971). ~ ~ t h o d r a i r o bircvrrcd i n oregon s t a t e u n i v e r s i t y (1977a) and USACE (19761.

.These data .re e higimr priority in Oregon estuaries classified by lCDC for Shall.," or Deep Draft D e u e i o w t than *hose oiesrified as Natural or conserva~ion. ~ o ~ e v e r , 421 data needs ere re2syent to the r e s o v r c ~ inyentory and s b v l d be included if the infomarion is avaiiable.

. . ... . . . ~. bu!luno. ranjonu! ruo!le3o! 6uwe uor!leduo3 lo, q2eoldde ie!~uan!)u! pue)

a ~ ! ~ e u , a ~ ! ~ ) . a p ! l peaq aqa 02 ~ ~ e ~ a r a aya $0 q3nm .ra!a!unuwoa !esleol3!rn 4 0 hI!ruaP pue ' u o ! x n q ! l l r ! p a>uepunqe snjzs

a41 ual) ruo!l=na!a !ep! l PUe .(.,SIN~WIO~S,, ! a l v l a=rl 'uo!l!rodma~ aq l pue adAl alellrqnr uaanlaq d ! q i -1% 'uo!xnq!AX sad*> l u ~ ! p a r ' r a ! l ! u ! l e r 10 a6uel ayl )o 3! lr! la l2e>q? .uo!le!a> a]en!en- o i .ra!~enlsa uo6alg u! ra!?adr - s ip 'UO!i!lOd

sa!dlues ado, i o 4 ruo!zezr !ep!xqns PUB l ep !uaau ! >=alas 1e61eor2!u =!uiuaq lo Al ! r lan !p aqx au!mlal=P o~ .uo> A l !unuwo3 'e*

.($L611 JaP!anua!!oh PYe (8961) I"owed pus pue!q3!'lh u! r a r i l e u e !!hqdolo!q> l o ) r p o q l a ~ .(0961)

P Y ~ ! ~ = ! ~ I Z Pue ( 9 L 6 ! ) -piemuallon U ! p a q ! n r a p rpoqiaw uo!l>npo,d '(a,e,,nrqns pue a,e,,ns) Al!rua>u! Z V S ! ! Jol!uoW

.ahoqe e [ # r p o q l W " ! paq!,,rap rar* [e"e lo4 *Ilua,Jn>uo3 ratdues raze. x>al lo) -wolaoq 02 a 3 e ) ~ n r r o ~ ) rq ldap [Planar

3pn!>u1 .ap!x ,o peaq aq) qlnw h l e n ~ r a aqx puohag suo!>e%s xe 'a!,h> !snuue auo ueqz a ~ a u la, ~ i q e i a j a j d '%luau

. a~nreau h!q~uau aqel .sanb!uy~a> uo!wqn=u! w a p uo lo qel pa~ia4ald rwaualnreau "? is u i i ~ j e i a u a . 1 .raze> uo!)

-3npold uolque!dolhqd 40 rpoqlau ua6Lxo i o ain ' A l ! n ! l -3npold uolque!dolAqd ,o ra !pn i r lo, uo6alo u ! rUo!l!PY07 a"!,.nlsa ,o a="*, aq3 40 an!leluasa,d., ra! ,enlra >>atas

'(8961) SuolJed p"e puetq,!ns Y ! ~ a s ~ ~ e u e aua!iznu lo) r p o q x a ~ . i ! ~ u a ~ ~ n = u o ~

ra~duer ~ a a e m jo * ~ ! ~ ! ! e r pue aamle~adwax .(a>eqdroyd 'axe, _!!!L .e,uOUIYe 'al!,l!Y 'alell!") IYO!lellYa,Uo3 l"a!ilnu

alnreaw '(zL6!: ~ a d a ! l q = s pue ($161) lap!a'*ua!!Yn U ! paq1,,*ap ranb!uq,al Bu!l"no, pue S"!,~"PS 'A(3ualin3

.uo:, u o a ~ u e l d w z atdues . r l a n a l 1q6!1 pue ap!a 03 anp ruo!le!~en a ~ n s e a u ol 6u!)duer inoq.$z Al 'a l~enp 'al>A3

lenuue auo ueyz S A W h!qela)aid .rqead !euorear 6u!lnp ~ ! ~ u a n b a q alav pue ~ ~ q a u c a >seal l e i a h ~ n ~ - ~ a ! d m = s

mdwng.a*~el) qz!" la" uolqueld 6u!nol la satdues lalen a ~ o q n 6u!l=s!!o3 a p ! ~ 40 peaq aq i oz q l n w Alenxra a w

p u o ~ a q suo!xels pax=a!ar l e vloaioq pue a7ejrni l e ahdues

3V.11V083!U ' W

- r a 3 ~ n o g exeoppowa* pazraSns eleo aqx j o aon r p a a ~ eleo

'(.,H$I~,, -as) h a n ~ n r qr!) j o u e d r e rpaq js6(e l o l e v 40 F u o l l e ~ i 6u>#nell ~ / D U R 6ulu8ar amn(=ul 'rAsnlnr

.. . . 1!1;3'.(816; ;;fbo'.6:a) r d w 1 ~ ~ ~ ~ ~ ' l woo ~ o l ) ~ s a ! l e n % ~ ~

h u m ~ o j a l g e ~ ~ e n e uo!xnq! l l r !p (e61eoiaeW ' ( ~ 9 6 1 ) IUDl'ed pue puel3=!Jls u! rashleuv .ha!u!les pue , a ~ n l e l a d o a l

' (a~eqdsoqd ' e ~ u w e ' a z ! ~ > ~ u .axed~!u) rarhleue l u a l l a n u do4 rAahlns l e61m43m q l ! n K( luai ln3uo3 ra ldver la3M 33a1!03

-ssewo!q a ~ a u ~ z r a pue ra!=ads h j1 luap1 03 'ol=h= lenuue avo veql a l w l o j h l q e l a j a l d 'h lq luau oldues ~000'z1:1

20 ate=$ ze d w pue uorear 6 u ! ~ ~ 6 aqa )o 7e.d ae ro loqd 1e!>ae u o ~ j rpaq lep l lqns m l l e q r pue !ep!x>azu~ jo a6e>ano=

un.\xe. a l w ! , r ~ ..PI> j o psaq aqx 03 i,en2na aq l j o w n a u aq) m d j ruo!?ena!a !ep!> pue '(,,PIN3W1(13L, I *!qel

ass] ..dhl lualp.s ' r a ! l ! u ! l e r ,o a6"el aqx $0 a!zr! .>.13eleq3 S u o l l e l r 6ul~dw05 leplxqns PYe lep ! l Ja lu l I3a lsS

.(q?f;l) 035sYn UI paq1:"sap Osle rarhleue I lAqdlo lq3 '(5961 9961) la*l*N Pue (6L61) O 3 I O Y n '(bL61) "P1w"'lloA O!

pasrn=s!p r p o q l w h~ !n ! l>npo>d pue 11hqdo~olq3 '(a'eJJnSq"2 a 3 ~ j ~ n s ) ~ l i s u a a u ) xq611 ~ a l ! u o y 'anoqe e l # rpoqlau "1

p a q l ~ > r a p re rarh let le ~ a j h ~ a u a ~ m ~ u o > ra lduer >ale* i = a l l o 3 (.raae>iaqnr le!:! j !ve 6 ~ 1 % " ( rawmiz ra r rewolq) u o ~ a e z .luolo, j o ale, ranlonul q,eordde a ~ ~ j e u ~ a z ! ~ ] 'h,enlra

a q l i noq6no~q% radh l >uw!pmr psz3alar l o j svo!?e%r l e p ! l -qnr pup l e p ! z ~ a ~ u ~ apn(3u1 q,!qn *a l>h> lenuue suo ueqa

a ~ a u l o ) h ~ q e ~ a j ~ d . ruo1>eulwlawp h ~ q w a u axen ' p a u a j -316 re le l l rqnr l e l n l e u uo r o [ % ! u n w 3 j o h ~ ! ~ ! l = n P o J d

e~n%s;fiu 02 ranb!uy,aa ue6hxo 20 3 "27s "I ~ h ~ ! n ! l ~ n p o J d ~ e K l e o l = ! u =lq luaq 40 ~ a ! p n ~ l ' ~ o j uo6adp u! ruol l !puo3

a u ~ ~ e n ~ s a 10 am.2 a q l j a en lxe lus ra lda l rol,sn%ra i=a las

.(Molaq I+# "3) * > l n ~ ~ n p o > d pue do,= 6ulpuelr IDXOI JIO~I YI ~ ~ l p ~ o m e ~ l ~ u n u u o , le61e j o sdha q=es $0 e=ue>,odul! a n ! i p & a aqx ou!vl>a>ap 01 ' S U O I ~ I P Y O =

i e a u a u u o ~ ~ n u a qitm rpaq l e s l e $0 u o ~ a ~ s o d u m Pue .s rwo !q . u o 1 l n q ! ~ l s l p a&sladlo:, 01 ' h l e n l r a o q l

UI sa!=adr le61e0130. j D h l !waA!p '41 o u l v l r ~ l a p 01 .I8011 la3>noTa)( eYllmn1S3 5031 SqI U I paJl"bSl

m .e6le j o ,,sx=e,> lore",, h j l l u a p , 0 1 'w2shs "o l l .=! j ! r re l3 i s l l q e H oulr .n ls~ "oS0,o sq3 ,o

la*.( r re l3qnr eq l "1 ,,rpaq ,!lenbe,, r e psu1jap a l e ~ " I U M ' 'am= $01 ire.! ae ~II* rewe h,~zu*pl 01

\ , ,. . . . - . . ...I A,,., ,,,, ,D wed 3s rp.9 s5-16ear dorm l o rewe "1 ruo1aszr B u l i u r ~ > 4o)pun 6ululor sVnl>ul '1rs46.** Jo is!,!"

..pelg 01 paq,ezae r a m , q a a , ~ ~ ~ ~ =P~I,YI OIIP ptna(r 6u1tdwss ' l irt i PU= .n",,o, rrPibDar 41!" .rA=uns (.,s~wgu~agr.. I 31se1 aal) 3-!wr Vue (,,S31'Eds

.31)1 111,, .le,q.lhrul .,qxYaq ,. > l e d re rpaq srei6e.r i o i e ~ q e u m n u ~ =!qxuaq lo4 aeziqeq e re ~ a ! l ! ~ n u u a ~ pa>n!,osse *a!,Sds

lo,- Ulq1!* IYOllels 6YIldwe6 qS16 10 a103 3!U1Y3q aP"L3"l 11e16~31 s=ue>ioduj an!lela> a w au!m,a~ap oi ~ w ! u e *,! luap~ i

u l 5 1 (1161 YOllDH pYe ue610~) ra ( len3ra rl ielal l Pun :1SIIS

aqx ,o s a l e ~ q a u a n u ! pue saqr!, 40 hanrnr v ' ( s q @ ~ = '6.a) r a ~ o ~ q a l ~ a ~ u ! a l i q a u i a 6 ~ e 1 pue ( , , ~ g ~ j , , ear) us!) hahlnr

0% rlauueq, q r ~ e w pa l9a la r us ruo!xelr d e l l qrl, la Ku!ular apn13u1 '(,,s~vwKvw,, aas) rlevwelu h 4 1 l u a ~ ! 02 r ~ o q l w

G u ! d d e ~ ~ lo 6u!luno= as" '(,,SOUIS,, aar) AahAnr p l ! q l o lled r e r a q s l w u! rluno= PA!^ PI*!, aPnI=YI '(,1531W8311(3A

ear, nanlnr a,e,qal,aAu! 40 lied r e rjauueq, qrlew pue q w e u u! r u o l ~ e l r su! ldues ~ e ~ p e n b lo 'qe16 'a202 >!q~uaq

a p n l u l pue sarrei6 q r ~ w uo 6 u l ~ ~ n m o ra>eiqaxlahu! h4 i luap i

'($161) "0510 pue a l ~ e u l , o ~ u! hog 500) l o xuuisrarre l e > l ~ o ~ r ! q 40 aldulex3

.(snoqe I # aar) s"or!,ed.o, lvanbarqns 20, au11aseq e q s ! l q e z q .(1961) . l e l a u a w ! ~ pue 'soaoqd l e t l a e ' (Aawns I a q S l w 1.3 eel*

uee30 l e u o l l e ~ h l l u a l l n = ) r l i e q ) h a u n s =!lapoag pus %roo1 . r ~ r e a ~ w l lo r a s r o ~ x e l ~ q e q 10 same" srasre o~ pue u o l l n q ! ~ > r l p u ! p ( o uo l ) ra!lenlra l a61e l w o r 20) a l q e ~ l e h e elep ! e 3 ! ' 0 l l l ~ .iano> pue u o ! l n q l ~ l r ! p u! rsGueq> au!wlalap ol ra6ueq3 le3!loar!H '(

'(89611 W G ~ H pue Jaui!w UI

parsn=r!p sporllavl w o s ' (8161)" le l a I a V a l j Pue '(8L611 moo '(CL6L) u0s~a44ar pue r u ! w (5161) ues'a&iar uo l4 a lqe - ~ ! e n e radh l q r ~ e v alums lo, elea ' ~ a n a 2 pue uo! lnqlJ ls !P u!

ra6ueq3 plo3al 02 papaau r e palepdn rhan ln r le! la\ ( '(8961) r u a r ~ e d pue P Y ~ ~ ~ , I J L S UI sashleue l u a ~ ~ l n ~ ' h l ! u ! l e r Pue

'amle~admaa ' r a q r i w p a p m l l pue slauueq= a p ~ x u1 (aleqd a o q d 'eluauue ' a ~ ! n ! u * a % e u ! u ) suo!~e~xua~uo= w a ! > l n u

a u ~ u ~ a z a p 02 ra lduer sa!,sds pue s r w o l q qz!n hL lua l ln3 -003 ra ldves ale^ ma1103 . s p o q ~ w h a n ~ n r pla!, Jolpue

h ~ & w ! u e l d hq a d h ~ q r ~ e o q3ea lo, a6e~ano3 helo> a%eul!xr3 . d w aseq 0 0 0 ' ~ 1 : 1 YO sadha q r ~ m l o u o ! l n q ! ~ l s ! p dew

.uor!~edwo= 201 r ~ e a h anlxn=aruo= a,w l o a% so) Alqela4ard '!le, h i l e a i o l-nr a q l S u ! ~ n p h l e n l s a a q l inoq6noJql

p a ~ n p u o 3 aq p ~ n o q s r h a n ~ n r p la14 pue hqde~boxoqd 1e12av

' r lez!qeq q r x u l o dew !saqr lW paqlp

GUIP~I~YI ( q U W q n ~ q s pue . q r o q

'a les no1 pue 1161~) lorw

.uW Al !u ! le r pue aJnle laduul l o I !uq ( .(8961) O;WYO Y I

P=qll=r=P %Pal l= 6 u l l a e s ' ( , , 3 v s ~ v o ~ y ~ n , a*') Alluaidnauo= ~ o ~ ~ u e l d o x ~ q d aldues ' s laha l ~ 6 1 1 Pue aP! l ol SnP

ruo!ls!ren wnrew 03 1n4a1n OIIP 6u!ldwer may-111 h I l o l l e n D .e1?A= lenuue auo ueqa ;nau ro) A l q e l q a l d 's3uep

.unqe l ~ n ~ e l pue u o ~ l u ~ l d m z w a d ,o r p o l ~ e d 6 u l ~ n p A lwanb -314 a ~ a u pue L ~ q l u a u I r e a t xe Aan~ns '~o ldu le r mdun8

-~XJDI) q11* lau u o z x u ~ ~ d ~ Y I * O ~ 10 i e lduer ~ 3 1 e m aloqn 6Y!13e1103 ' a p I I 40 peaq Sq1 0% Alen l ra oq l lo q l n w oql p u o ~ e q suo!le>s paa3elar ae wnoq puo a x j ~ n r ze aldwes

'(8961) r ~ q 6 n ~ pue i a u l ! " u! p a r m 3 r ! p rpoqlaul leleY=S ..(LL61 YOlloH pUe ue6240 r a l p n l r Al !n! l3npold luanb

-arqnr u! r p o q l r v 02 apln6 e r e a ~ l a r plnoqr pUO Yolleuuo) -ul 10 ?dAl $141 10 -5 ap!nord il!n ra!lenlr.1 ~ 0 6 ~ 1 0 a o l q l

, . . . ... , pale pue ~ x ~ s u a p qww io r & a u ~ z s e q31m s l e l s l l o = 01

.ra!pnls 1e3!6ololr!q lo , pal.a(lo" ralduler l l n p e PUL rAanlnr LenAel q x ! ~ h ! > u a > ~ n = u o ~ amze~sduaa pue A~IYIIDI IOI!UOW

.s.lduler .el> lo rualx=ar u ! q l MA, f iu~u*=dr $0 p o l ~ o d ~ z a r ~ x o ~ d d e pve ~ u w d o ( . ~ a p lepsu06 au!uualep pue rluno3 66s a ~ e l d ~ o , .salpnls le3!60!oarlq r o j se!denlra an!~eluaralde,

ma, e u l tu9eo~dde r ~ o ~ r a d ~ u l v r e d r re h l > u a n b a ~ elm)

(6" l u ~ s d r Kul>us -"I,YI "013.4

IslV*YWl!hY* pus) s ~ l 3 a d s us13

Isua!ls=>=e> pve lel"'awO3 204

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