Species Profiles: Life Histories and EnvironmentalRequirements of Coastal Fishes and

Invertebrates (South Atlantic): American oyster

Item Type monograph

Authors Burrell, Victor G.

Publisher U.S. Army Corps of Engineers, Coastal Ecology Group, WaterwaysExperiment Station.

Download date 08/09/2021 22:27:10

Link to Item http://hdl.handle.net/1834/21292

MFEYEFJCS COPY Do Not Remove from the Library

U. S. Fish and Wildlife Service h l h l C m w

Biological Report 82 (I 1.57) 700 Cajun Dome Boulevard TR EL-82-4 July 1986 Lafayette, Louisiana 70506

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (South Atlantic)

AMERICAN OYSTER

Coastal Ecology Group Fish and Wildlife Service Waterways Experiment Station U.S. Department of the Interior U.S. Army Corps of Engineers

Biological Report 82(11.57) TR EL-82-4 July 1986

Specles Prof 1 les: L i f e H ls to r ies and Env lronmental Requirements of Coastal F l shes and i nvertebrates (South A t l an t i c )

AMER l CAN OYSTER

V lc to r G. Burrel I, Jr. South Carol 1 na Mar l ne Resources

Research i n s t i t u t e 217 Ft. Johnson Road Charleston, SC 2941 2

ProJect Manager Carrol l Cordes

ProJect Off icer Dav I d Moran

National Wetlands Research Center U.S. Fish and W l l d l l f e Service

101 0 Gause Bou l evard S l idel I, LA 70458

Performed f o r

Coastal Ecology Group U.S. Army Corps of Engineers Waterways Exper iment S ta t ion

V lcksburg, MS 39180

and

National Wetlands Research Center Research and Development Fish and W i l d l i f e Service

U. S. Department o f the I n t e r i o r Washington, DC 20240

Thls ser les can be referenced as fol lows:

U.S. Flsh andWlldlifeServ1ce. 1983-19-. Specles profiles: Ilfe hlstorles and environmental requirements of cqastal fishes and invertebrates. U. S. Fish Wlldl. Serv. Blol. Rep. 82(11). 1I.S. Corps of Englneers TR EL-82-4.

Thls prof lle can be clted as follows:

Burrel I, V.G., Jr. 1986. Species prof i Ies: I lfe hlstor les and env ironmental requirements of coastal f I shes and invertebrates (South At1 antic)--Arner ican oyster. U.S. Flsh Wlldl. Serv. Blol. Rep. 82(11.57). U.S. Army Corps of Englneers TR EL-82-4. 17 pp.

PREFACE

This species p r o f i l e i s one o f a ser ies on coastal aquatic organisms, p r i n c i p a l l y f i s h , o f sport , commercial, o r ecological importance. The p r o f i l e s are designed t o provide coastal managers, engineers, and b i o l o g i s t s w i t h a b r i e f comprehensive sketch o f the b i o l og i ca l charac te r i s t i cs and environmental requirements o f the species and t o describe how populat ions o f the species may be expected t o react t o environmental changes caused by coastal development. Each p r o f i l e has sect ions on taxonomy, 1 i f e h i s t o r y , ecological r o l e , environmental requirements, and economic importance, i f appl icable. A t h ree - r i ng binder -is used f o r t h i s ser ies so t h a t new p r o f i l e s can be added as they are prepared. This p ro j ec t i s j o i n t l y planned and f inanced by the U.S. Army Corps o f Engineers and the U.S. F ish and W i l d l i f e Service.

Suggestions o r questions regarding t h i s r epo r t should be d i rected t o one of the f o l l owing addresses.

In format ion Transfer Spec ia l i s t Nat ional Wet1 ands Research Center U.S. F ish and w i l d l i f e Service NASA-Slidell Computer Complex 1010 Gause Boulevard S l i d e l l , LA 70458

U. S. Army Engineer Waterways Experiment S ta t ion At tent ion: WESER-C Post O f f i ce Box 631 Vicksburg, MS 39180

CONVERSION TABLE

M e t r i c t o U.S. Custanary

Mu1 t i p i p !Y To O b t a i n

m i l 1 i rneters (mn) cen t imete rs (an) meters (m) k i 1 ometers (km)

2 square meters (m ) 10.76 square k i 1 m e t e r s ( km2) 0.3861 hec ta res (ha) 2.471

l i t e r s ( 1 ) c u b i c ineters (m3) c u b i c meters

m i l l igrams (mg) 0.00003527 grams ( g ) 0.03527 k i log rams ( k ) 2.205 m e t r i c tons f t ) 2205.0 m e t r i c tons 1.102 k i 1 ocal o r i e s ( kca l ) 3.968

inches inches f e e t m i l es

square f e e t square i n i l es acres

gal 1 ons c u b i c f e e t acre- f e e t

ounces ounces pounds pounds s h o r t tons B r i t i s h thennal u n i t s

Cel s i u s degrees 1.8(Oc) + 32 Fahrenhe i t degrees

U.S. Customary t o M e t r i c

inches 25.40 inches 2.54 f e e t ( f t ) 0.3048 fathoms 1.829 m i l e s ( m i ) 1.609 n a u t i c a l m i l e s ( m i ) 1.852

square f e e t ( f t 2 ) acres 2 square m i l e s (mi )

ga l 1 ons ( gal ) 3.785 cub ic f e e t ( f t 3 ) 0.02831 a c r e - f e e t 1233.0

ounces (02) 28.35 pounds ( l b ) 0.4536 s h o r t t o n s ( t o n ) 0.9072 B r i t i s h thermal u n i t s ( B t u ) 0.2520

m i l 1 imete rs cen t imete rs ineters mete rs k i l m e t e r s k i 1 one te rs

square meters hec ta res square k i l o m e t e r s

1 i t e r s c u b i c q e t e r s cub ic meters

grains k i 1 ograms m e t r i c tons k i 1 ocal o r i e s

Fahrenhei t degrees 0.5556("F - 32) C e l s i u s degrees

CONTENTS

mEFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONVERSIONTABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . ACKN WLEDGMENTS

. . . . . . . . . . . . . . . . . . . . . . NoMENUATURE/TAXONoMV/RANGE . . . . . . . . . . . . . . . . . . . . MORPHOLOGY/IDENTIFICATlON AIDS . . . . . . . . . . . . . . . . . . . . REASON FOR INCLUSION IN SERIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIFE HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spawning . . . . . . . . . . . . . . . . . . . . . . Eggs a n d F e r t l l l z a t i o n Spat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adult . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GRWTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . COMMERC l AL HARVEST . . . . . . . . . . . . . . . . . . . . . . . . Populat ion Dynanlcs . . . . . . . . . . . . . . . . . . . . . . . . . . . . ECOLOG ICAL ROLE . . . . . . . . . . . . . . . . . . . . . . ENV IRONMENTAL REQU IREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S a l i n i t y . . . . . . . . . . . . . . . . . . . . . . . . . Dissolved Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H a b i t a t . . . . . . . . . . . . . . . . . . . . Other Environmental Factors

. . . . . . . . . . . . . . . . . . . . . . . . . . . L l TERATURE C l TED

F 1 GURES

Number hs

1 Amerlcan oysters, Crassostrea yLcglntca, frcm subt ldal and l n t e r t l d a l hab l ta ts In the South A t l a n t l c reglon. . . . . . . . 1

2 D l s t r l b u t l o n of predcnnlnantly subt ldal and l n t e r t l d a l oysters In the South A t l a n t l c reglon. . . . . . . . . . . . . . . . . . 2

3 A t yp lca l l n t e r t l d a l oyster bar showlng the dense growth canmon t o these areas . . . . . . . . . . . . . . . . . . . . . 3

4 I n t e r t i d a l oysters being picked by hand . . . . . . . . . . . . 4

5 Oyster landlngs 1880-1984 for the lndlv ldual States and f o r the reglon as a whole . . . . . . . . . . . . . . . . . . . . . 6

6 A mechanical i n t e r t i d a l oyster harvester being used t o r e h a b i l i t a t e pub l i c oyster grounds i n South Carolina . . . . . 8

ACKNOWLEDGMENTS

I thank Ronald Dugas and John Manzi f o r t h e i r reviews and many he lp fu l suggestions. I am g r a t e f u l t o Louise Hammes f o r typing the manuscript, Karen Swanson f o r d r a f t i n g the f igures , and George Stee le and Wi l l iam Anderson f o r photographic assistance. Thanks a1 so go t o Nancy Peacock f o r computer assistance.

Flgure 1. Amerlcan oysters, C r a s s o s s y L ~ h L c a , from subt ldal and i n t e r t i d a l habi ta ts I n the South A t l a n t l c reglon.

AMERICAN OYSTER

NOMENCLATURE/TAXONOMY/RANGE MORPHOLOGY/ I DENT I F I CAT I ON A IDS

Scientific name............Crassostrea y m (Flgure 1)

Preferred common name.........American oyster

Other common names......Eastern oyster and when r e f e r r i n g t o long, t h i n she1 led G. dqhb growing I n t e r t l dal ly, coon oyster

Class.........................Bivalvia Order........................Pteroidea Family.......................Ostreidae

Geographic range: Found I n sounds, bays, and estuar ies from New Brunsw ick, Canada, t o the Gu l f o f Mexico. Throughout most o f i t s range, it grows subt idal ly; however, i n the South A t l a n t l c States from about t he Newport River, North Carol i na, south along t he east coast o f Florida, it occurs p r inc ipa l l y i n dense, i n t e r t i d a l beds (Flgures 2 and 3; Galtsof f 1964; Abbott 1974).

Shell weight and shape can be h igh ly variable, ranging from heavy shel l and f a i r l y regular I n subt ida l s l ngl e oysters t o thin, elongated, and h igh ly I r regu la r i n i n t e r t i d a l oysters (Figure 1). The l e f t valve, which i s attached t o the substrate, i s usual l y t h i cke r and more deeply cupped than the r i g h t . The adductor muscle scar i s located pos te r i o r l y and i s gener- a l l y pigmented; no hinge tee th are present. Ostrea ~ i p e m s , o r horse oyster, c l ose l y resemb l es C. ~ k g h ~ k a , bu t the muscle scar i s more central l y located and not general l y colored, and small dent ic les are present on e l t he r s ide of the r l g h t valve hlnge. These dent ic les f i t I n to correspond 1 ng depressions i n the margin o f the l e f t valve. U a aquskIs averages only about 5 cm I n height, and therefore i s not o f conunercial in terest . I t i s most o f ten found I n hlgher s a l i n l t y (35 ppt ) than

NORTH CAROLINA

SOUTH CAROLINA

M I L E S

KILOMETERS

ATLANTIC OCEAN

F igu re 2. D l s t r l b u t l o n o f predominantly subtlcial and I n t e r t i d a l oys te rs I n t h e South A t l a n t l c reg lon .

F igu re 3. A t y p i c a l i n t e r t i d a l oys ter bar showing t h e dense growth common t o these areas.

C. y k g l n k a , bu t both species may co-occur I n s a l l n l t l e s as low as 20-25 p p t (Menzel 1956; Yonge 1960; G a l t s o f f and Mer r l l 1 1962; Gal t s o f f 1964; Po r te r and T y l e r 1974).

REASON FOR INCLUSION IN SER l ES

The American oys ter has been e x p l o i t e d cornmerclally s lnce t h e mid-19th century l n t h e South A t l a n t l c reg ion and cont lnues t o support a pran inent f lshery i n North Carol ina and South Caro l ina ( B u r r e l l 1985a; F lgure 4 ) . I t i s a l so an important rec rea t i ona l species (Moore e t a l . 1984).

Vast l n t e r t t d a l r e e f s constructed by oys ters a re significant b i o l o g i c a l l y and physical l y I n es tua r ies o f t h e South A t l a n t l c reglon. Fishes, crabs and shrimp a re among t h e anlrnals t h a t u t i l l ze t h e I n t e r t i d a l r e e f s wh i l e they a re

submerged f o r re fuge and a l so as a source o f food, f o rag lng on t h e many r e e f dwe l l l ng specles. Reefs, as they become es tab l lshed, modlfy tidal c u r r e n t s and t h i s I n t u r n a f f e c t s sedimentary pat terns. Further, t h e r e e f s con t r i bute t o t h e s tab 1 l 1 t y o f stream bot tuns and banks and t o t h e border lng marsh as we1 l (Wel l s 1961; Bahr and Lan le r 1981; Cake 1983).

L l FE H l STORY

Water temperature s t 1 mu l ates gametogenesis and spawning i n t h e Amer ican oys te r and c r I t l c a l temperatures vary over t h e geograph lca l range. Spawn1 ng beglns a t 1 6 . 4 O C i n Long I s l a n d Sound, 20.0 O C i n more s o u t h e r l y areas, and 25 O C i n t h e G u l f o f Mexico (Loosano f f 1969). McNulty (1953) r e p o r t e d t h a t South Caro l i na i n t e r t i d a l o y s t e r s

u n t i 1 temperatures reached 26.0 O C

( I n g l e 1951).

F igu re 4. I n t e r t i d a l oys ters being p icked hy hand. Th is i s fhe c h i e f mesns o f harves t ing i n t e r t i d a l oysters.

spawned when sur face temperatures ranged from 18.6 O C t o 25 OC. B u r r e l l e t a l . (1984) found t h a t both sub t i da l and i n t e r t i d a l oys ters were r i p e throughout the year. Spawning was i n t e r m i t t e n t a t sa l i n i t i e s averaging 25 p p t o r h igher from May t o November. I n a lower s a l i n i t y area ( l ess than 20 pp t ) , spawning o f sub t i da l oys ters appeared t o be r e s t r i c t e d t o one major pe r i od i n midsummer (temperature above 30 O C ) , w h i l e i n t e r t i d a l oys ters spawned dur ing two major periods: one i n e a r l y summer (>30 O C ) and one i n fa1 1 ( > 2 3 OC). Durant (1969) repor ted t h a t the spawning season i n Georgia l a s t e d from May, when temperatures reached 23 O C , t o November. I n Apalachicola Bay, F l o r i d a , spawning, as i nd i ca ted by the appearance o f young oys ters on p lan ted 'she1 1, began

c n r nri 1.1nnk n f Anril w h n n th?oughout the year. Spawnlng was i n t e r m i t t e n t a t sa l i n i t i e s averaging 25 p p t o r h igher from May t o November. I n a lower s a l i n i t y area ( l ess than 20 pp t ) , spawning o f sub t i da l oys ters appeared t o be r e s t r i c t e d t o one major pe r i od i n midsummer (temperature above 30 O C ) , w h i l e i n t e r t i d a l oys ters spawned dur ing two major periods: one i n e a r l y summer (>30 O C ) and one i n i i . 0 n ..-,, L / i n c n \ ,,,,,+,A

Spawnlng i n females i s t r i g g e r e d by re lease of sperm i n t o t h e water column (Andrews 1979; Bahr and Lan ler 1981 1. Oysters may spawn several t imes dur ing a season; i n t e r m i t t e n t p ro t rac ted spawning i s t y p i c a l i n I n t e r t l dal oysters. A rap1 d increase 1 n temperature a l so o f t e n t r i g g e r s spawnlng i n oys ters (Hidu and Hasklns 1971; Dupuy e t a l . 1977). I n t e r m i t t e n t spawnlng I n I n t e r t i d a l oys ters may r e s u l t frcm g r e a t l y f l u c t u a t l n g temperatures on i n t e r t i d a l reefs. Lunz ( 1960) repo r ted va r !a t i ons o f 16 "C w i t h i n a few minutes. Gal t s o f f ( 1964) est imated one female discharged 114.8 m i I I 1on eggs a t a s l n g l e spawning. Number o f eggs re leased v a r l e s w l t h s i z e and cond i t i on o f t h e female and number o f spawns (Ga l t so f f 1964).

Eggs o f Crassostrea a r e canpressed and pear-shaped measuring from 55 t o 75 p m i n t h e long a x i s and 35 t o 55 p m wlde (Ga l tso f f 1964). Tro- chophore la rvae develop w l t h i n 6 t o 9 h a f t e r egg f e r t i l i z a t i o n , and metamorphose i n t o s t r a i g h t hlnge o r v e l i g e r larvae a t 12 t o 16 h a f t e r f e r t l l l z a t l o n (Gal t s o f f 1964; Dupuy e t a l . 1977). The s t r a i g h t h lnge larvae and subsequent stages a r e p iank ton l c and remaTn Tn t h e water column f o r up t o 3 weeks, w l t h p lank ton i c t ime vary ing w i t h avai l able food, water temperature and sal i n i t y (Bahr and Lan ler 1981; Cake 1983). Oyster l arvae a r e t ranspor ted throughout es tuar Ine systems by t i d a l a c t ion. Larvae concentrate near t h e sur face on r Tsing $ ides and near t h e bottom on f a l l i n g t ldes , thus Increaslng t h e l r chances o f belng more w ide ly distributed i n an estuary and no t being swept ou t t o sea (Car r i ke r 1951;

1 06A 1071 !^e'i!$G I arv'aewn'24 "79 Vorni & h a l t e r f e r t l l i z a t l o n (Gal t s o f f 1964; Dupuy e t a l . 1977). The s t r a i g h t h lnge larvae and subsequent stages a re p i anktonlc and remaTn Tn t h e water col umn f o r up t o 3 weeks, w l t h p lank ton i c t ime vary ing w i t h avai l able food, water temperature and sal i n l t y (Bahr and Lan ler 1981; Cake 1983). Oyster l arvae a r e t ranspor ted throughout L . . L L . . I --A,-.-

approxlmately 300 p m I n diameter and I s charac ter lzed by a we1 l -devel oped f o o t and two eye spots. The f o o t enables t h e l a rvae t o crawl on t h e bottom t o seek subs t ra te s u i t a b l e f o r attachment. The e a r l y s e s s l l e stage o f t h e oys te r I s ca l led spa t and t h e process o f attachment I s ca l led s e t t l n g o r s p a t f a1 1 . The ped l v e l l g e r may exp lo re several s i t e s be fo re permanently a t t a c h l n g t h e l e f t va lve t o t h e f l n a l subs t ra te w 1 t h cement produced by a l a r v a l organ, t h e byssus gland.

Ped lve l l ge rs r a p i d l y lose many l a r v a l f ea tu res a f t e r attachment. The f o o t and eye spots a re l o s t and t h e vel um I s Incorporated I n t o p a r t s o f t h e a1 lmentary system (Gal t s o f f 1964). Attachment subs t ra te may be any hard substance such as glass, concrete, b i t s o f rock o r o t h e r she1 I. Oyster shel l I s most o f t e n chosen by t h e ped lve l Iger. Oyster p l a n t e r s d l s t r l b u t e mol I uscan she1 1 ca l led c u l t c h f o r t h i s purpose (Bur re l l 1985b). Larva l s e t I s stimulated by an Increase I n temperature (Lu tz e t a l . 1970; Hldu and Hasklns 1971). Bahr and Lan le r (1981) repo r ted t h a t w h l l e oys te rs tend t o be photopos I t l v e du r lng l a r v a l stages, they may become photonegatlve as water temperature I ncreases.

Heav l e s t spa t f a1 l may occur be l ow mean low water I n t h e South A t l a n t l c States; however, s u r v l v a l I s much g rea te r a t j u s t above mean low water (Chestnut and Fahy 1953; McNuIty 1953). Lower s u r v i v a l below mean low water may be a r e s u l t of p redat lon o r o f f o u l i n g by compet i tors and cu r ren t - borne s l l t (Dean 1892; Chestnut and Fahy 1953; McNul t y 1953; L l n t o n 1969).

Adult

Once attached, oys te rs remaln I n t h e same l o c a t l o n throughout l i f e unless they a re moved by man. I n t h e

South A t l a n t l c States, oys te rs ( w l t h on1 y a few except ions) occur I n I n t e r t i d a l beds t h a t become es tab l lshed when c o n d l t l o n s permlt; t h a t Is, when sa l l n l t y , cur ren t , food, suppor t l ng substrate, and t u r b 1 d l t y a r e s u l t a b l e (Bur re l 1 e t a l . 1981; Cake 1983). These beds prov lde h a b i t a t f o r numerous estuarine anlmals (Wel ls 1961; Dame 1972, 1979; Bahr and Lan le r 1981; Cake 1983; Manzl e t a l . 1985). Stream channel s a r e 1 n f I uenced by oys te r ree fs , wh l c h serve as e l t h e r a stab11 l z l n g l n f luence o r mod l fy lng f o r c e as these r e e f s grow. Subt ldal o y s t e r beds do occur na tu ra l 1 y b u t r a r e l y I n Southeastern Sta tes and prov lde h a b i t a t f o r o the r shel l f i s h such as hard clams, mercenarla (Bur re l 1 1977).

Adu l t oys te rs a r e usual l y d loec lous, b u t sex changes a r e f requent . General ly, year l l ng oys te rs a r e predom l n a n t l y males, b u t 01 der o y s t e r popu l a t I ons become preponderant 1 y femal es. Even I n oys te rs several years 01 d, however, sex r e v e r s a l s a r e common and females may become males again o r v l c e versa (Gal t s o f f 1964).

GRWTH

I n g l e (1950) found t h a t growth o f American oys te rs i n F l o r i d a exceeded 100 mm i n 3 1 weeks; growth i n l eng th was g rea tes t i n t h e f i r s t 6 weeks a f t e r s e t t i n g . Palmer (1976) recorded increases i n average 1 ength o f Georgia oys te rs over a 7-month p e r i o d (November t o June): i n s u b t i d a l and i n t e r t i d a l animals, increases were 31.1 mm and 19.6 mm, r e s p e c t i v e l y , when beginning s izes were 10-19 mm and 10.2 mm; sub t i da l oys te rs grew 3.0 mm when beginning s i z e was 100 mm. Manzi e t a l . (1977) and Burrell et al. (1981) reported monthly growth o f 1 t o 4 mm i n South Carol i na oys ters . Growth i s c o n t i nu- ous throughout t he year , as f a r n o r t h as South Caro l ina , a l though i t slows apprec iab ly i n midwinter i n South

Caro l i na ( B u r r e l l e t al . 1981). Growth appears t o be most r a p i d i n summer ( I n g l e 1950).

Growth appears t o be greater I n subt ldal oysters than I n l n t e r t l d a l oysters; however, t h l s may be a resu l t of crowdlng on l n t e r t ldal beds (Burrel l 1982). G l l lmor (1982) found t h a t oyster growth was bet ter per u n l t lmmerslon t lme a t sane depths below mean hlgh water I n the l n t e r t l d a l zone than I n subt 1 dal beds. Protracted spanning seasons may also re ta rd growth I n I n t e r t l da 1 oysters because o f energy demands f o r t h I s ac t l v l t y (McNu l t y 1953). Lunz ( 19551, Anderson (19761, and Manzl e t a l . (1977) found t h a t growth I n sat t ponds exceeded t h a t I n adJacent waterways.

COMERC I AL HARVEST

The oyster Industry has prov lded

employment f o r many watermen In the South A t l ant l c States (Magglonl and Burrel 1 1982). I n the ea r l y 1 9 0 0 1 ~ ~ annual landlngs general l y exceeded 10 m 1 l l Ion pounds and peaked a t near ly 20 m l l l l o n pounds I n 1908. Production then decllned s tead l l y u n t l l 1970. Fran t h e mld-1970,s t o 1984, landlngs remained f a i r l y steady a t about 2 m l l l l o n pounds (Bur re l l 1982, 1985a; F lgure 5). Several pr lnc lpa l causes of t h I s decl lne have been suggested:

1. Loss o f labor t o competing Industr les.

2. Grow Ing area l o s t t o product Ion because o f pol l u t Ion, changes I n sal l n l t y patterns caused by coastal development and changes I n f arm1 ng and fo res t ry pract Ices.

3. Management practices t h a t do not encourage good husbandry.

4. Lack o f modern technology I n cu l ture, harvest and process1 ng sectors.

1902 1908

- SOUTH ATLANTIC REGION . . . . . . . . SOUTH CAROLINA - -NORTH CAROLINA - - - - GEORGIA - . - -EAST COAST OF FLORIDA

F igu re 5. Oyster land ings 1880-1984 f o r t h e i n d i v i d u a l S ta tes and fo r the reg ion as a whole (F i she ry S t a t i s t i c s of t he Un i ted States, 1880-1979: f i s h e r y s t a t i s t i c s o f f i ces f o r S ta tes invo lved.

5. Laws t h a t do not encourage Increased 1 nvestment In the 1 ndustry.

6. Flnal ly, and probably most Importantly, the lack of markets f o r t he l n t e r t l d a l oyster. Thls s h e l l f l s h does not lend I t s e l f t o raw shucklng and must therefore be opened ch le f l y by steam. The meats are then canned as a cooked product t h a t has a very IlmlPed demand and must canpete w l th cheap Imports. The number of cannerles has dropped I n South Carol 1 na a1 one f ran 16 I n 1905 t o one today (Kel th and Gracy 1972). The other v lab le market f o r l n t e r t l d a l oysters I s sales t o lnd lv lduals o r groups f o r oyster roasts. These roasts are t r a d l t l o n a l coastal socl a1 events and o f f e r l l t t l e potent la l f o r expand lng the market.

B lo log lca l problems such as dlsease, recruitment f a 1 1 ure, and predators Inf luence production of southern I n t e r t l dal oysters less than northern subt l dal stocks. An overabundance of set and hlgh surv lva l I s a greater probl em fo r the southern oyster grater. The l n t e r t l d a l ree fs tend t o become overgrown w 1 t h smal 1 and densely crowded oysters. Llm l t ed markets compound t h e problem because many more oysters are aval lab le on ree fs than can be sold and, therefore, the reefs are not harvested regular ly .

Oyster meat y i e l d per volume o f she l l stock i s lower i n the South A t l an t i c States than i n other oyster- growing areas because o f the poor condi t ion o f the oysters due t o a prot racted spawning season, and because the crowded oysters i n the i n t e r t i d a l zone are small , elongate, and t h i n shelled. Y ie ld i n V i r g i n i a oysters averaged 6.0 t o 6.5 p i n t s / bushel raw shucked, wh i le i n South Carol ina canneries the y i e l d was on ly about 1 p i n t per bushel (Lunz 1950).

Each State of t he South A t 1 an t l c reglon has a program of sane s o r t deslgned t o rev l t a l lze the1 r oyster I ndustry (Cowman 1982; Magg Ion 1 and Burrel I 1982; Mu nde n 1982).

Mechanical harvesters are be1 ng used I n North and South Carollna t o move oysters f r a n areas closed t o harvestlng and from very dense beds t o pub1 l c grounds I n order t o Improve stocks I n these areas. (Flgure 6; Munden 1982; Manzl e t at. 1985).

Sel I e r s and Stanley (1984) revlewed mortal Ity of larvae I n subt ldal grcwlng areas. They noted t h a t mortal l t y var les g rea t l y accord 1 ng t o area, vu l nerab 1 1 1 t y t o predators and ln tens l t y of set. Nelson (1925) noted t h a t Iobate ctenophores fed on oyster larvae and t h a t abundance of ctenophores was Inverse1 y corre la ted w 1 t h abundance of oyster se t I n New Jersey waters. Spat mortality I s no t a problem I n the southern I n t e r t l dal oyster; 1 nvar lab1 y more spat survive than are needed t o repopul a te ree fs and, as mentioned, overcrowdlng and poor growth resu l t . Mortal l t y of spat I n North Carol lna and South Carol lna lncreased w l th depth belcw mean low water (Chestnut and Fahy 1953; McNulty 1953). McKenz l e (1981 1 cat cul ated surv lva l ra tes based on year ly changes I n popul atlon; In1 tl al approxlm2te spat denslty was 200 t o 10,00O/m , a t 1 t o 2 years numbers f e l 1 t o 300/m2, and a t 3 t o 4 years on ly 75/m2 remained. Burrel I e t at. (1981 observed In t r ays a t several loca t Ions I n South Carol lna t h a t year ly mortal l t l e s exceeded 50% In seed oysters 2 years o l d a t transplanting and less than 22% I n seed 1 year o l d a t t ransplant ing. I n another study o f South Carolina oysters (Manzi e t a l . 1977), adu l t oysters planted sub t i da l l y had surv iva l ra tes o f 85% t o 9 l% i n s a l t ponds and 92.5% t o 94.5% i n adjacent streams. Reisinger (1978) reported monthly mortal i t i e s ranging from less than 5% t o 40% i n a Georgia i n t e r t i d a l bed.

ECOLCG ICAL ROLE

Larvae are p l ankt lvores feedl ng

F l gu re 6. A mechan I c a l l n t e r t Ida1 oys ter harves ter be lng used t o rehab I l l t a t e p u b l i c oys ter grounds I n South Carolina.

p r l nc lpa l l y on smal l naked f lage l l a t e s and diatoms. Det r l t a l p a r t l c l es and bacter l a assoclated w l t h p a r t l c l es, and possibly, d i sso l ved organ lc compounds, may a l s o be o f n u t r l t l o n a l Importance t o o y s t e r l arvae (Gal t s o f f 1964; Bahr and Lan le r 1981; Cake 1983). Larvae a re I n t u r n consumed by a l a rge number o f predators t h a t l n c l ude copepods, ctenophores, Jel l y f I sh and t h e young o f f I sh and crustaceans (Nel son 1925; Andrews 1979).

Adu l t oys te rs a l s o feed p r l m a r l l y on phytopl ankton. P re fe r red s l ze o f naked f l age1 I ates se l ec ted by oys te rs was repo r ted by Haven and Morales-Alamo (1970) t o be 3 t o 4 pm. Under opt lmal cond I t Ions o f temperature and sa l 1 n I ty, an oys te r pumps water a t t h e r a t e o f 15 l /h. (Ga l t so f f 1964). The d a l l y volume o f

water f I l t e r e d by l n t e r t l dal oys te rs

I s n o t known, b u t presumably It I s l ess than t h a t o f s u b t l d a l oys te rs f o r no o t h e r reason than l n t e r t l d a l oys te rs may spend ha1 f t h e l r l lves o u t o f water. The extensive s a l t marshes border lng t i d a l creeks serve as n u t r l e n t and o rgan lc d e t r l t u s sf nks and t h e l r f l u s h l n g provldes a r l c h food source f o r oys te rs (de l a Cruz 1973; Manzl e t a l . 1977).

l n t e r t l dal o y s t e r r e e f s prov lde h a b l t a t f o r count less lnfaunal and ep l fauna l specles. Wel I s (1961) I l s t e d 303 specles from both l n t e r t l d a l and sub t l da l r e e f s I n North Carol lna; Bahr (1974) repo r ted some 42 specles o r groups assoclated w l t h l n t e r t l d a l r e e f s I n Georgla; and Dame (1979) found 37 specles and Manz I e t a l . (1985) I l s t e d 89 specles f o r South Carol I na l n t e r t Ida1 ree fs . Dame (1979) repo r ted t h e average number o f

2 I nd l v ldual s/m to2be 2,949, and Bahr (1974) 24,747/m of assocl ated animals 1 l v lng on l n t e r t l d a l oyster ree fs I n South Carol I na and Georgl a, respectively. Reefs also In tercept t i d a l currents and may profoundly a f f e c t the s u l t a b l l 1 t y o f adJacent areas f o r other species.

The density o f oysters grow lng I n l n t e r t l d a l ree fs almost def ies ccmprehenslon. Lunz (1 960) counted 5,895 oysters, 05 4.5 U.S. bushels, I n an area of 1 yd . In another study, he reported an average of 135.9 2-Inch oysters per square yard I n 117 samples (Lunz 1943). Bahr and Lanler (1981) estimated t h a t oysters alone accounted f o r approximatel y 87.5% of the b lunass and 48.1% of t he resp l ra t l on on an oyster reef. Lunz's (1943, 1960) estlmates suggest t h a t t h l s value appears reasonable.

Many theor les have been put f o r t h t o explaln the success o f l n t e r t l d a l oysters I n the South A t l a n t l c States and the lack o f success o f subt idal oysters. These Include avoidance of predators such as dr 1 I 1 s ( h p l eura m, lbsaI&u -1, whelks (U carlca, B. cantculatum), crabs (Callfnectes sp. and fami ly Xanth 1 dae) , s t a r f 1 sh hkixdas forbest), f l sh (Rhtnoom bonasus, &qpnJi~ n m l s ) , and f Iatworms (- e J I I p t 1 ~ ) (Ba t t l e 1892; Carr lker 1955; Lunz 1960; Merrlner and Smlth 1979; Bahr and Lanler 1981; Sel l e r s and Stanley 1984). Bor ing sponges (Uhm spp. and annel I d worms (Polydora spp. ) , which cause considerable damage t o subt idal oysters, are not a problem i n the i n t e r t i d a l zone (Lunz 1947).

Other reasons t h a t may account f o r oyster reef concentratlons I n t he l n t e r t l d a l zone are the presence of more sul tab1 e substrates, more available food, less t u rb l d l t y , more su i tab le current ve loc l t les , higher spatf al I, excl us Ion o f sane disease-causing organisms, and genet lc d l f ferences leadlng t o physlologlcal

sel ec t lon (Lunz 1941, 1943; Haven and Burrel 1 1982; Burrel 1 e t al . 1984). Recent studies have shed 1 l gh t on two o f these conJectures. No evidence of genet lc d l f ferences between subt Ida1 and l n t e r f l d a l oysters f r an the same South Carollna r i v e r system was determ lned In an e l ectrophoret l c study by Anderson and Welr (W. W. Anderson, Department o f Molecular and Populatlon Genet 1 cs, Un I vers 1 t y o f Georg 1 a, Athens; pers. ccmm. 1. Burrel l e t a1 . (1984) found t h e lncldence and ln tens l t y o f ln fec t lon of subt ldal and 1 n t e r t l dal oysters by t he pathogen Perklnsus marinuP t o be of the same magnitude I n two areas of South Carolina; thus t h i s disease d i d not appear t o be l n f luenced by hab i ta t e l evat Ion. Other oyster d 1 seases, such as Delaware Bay dlsease caused by the haplosporldean Mlnchlnla nelsonf and seaside dlsease caused by the hap1 ospor Idean M. m s s have not been reported south of North Carol 1 na along the A t l a n t l c coast.

Subt I dal oysters compete f o r grow lng space wi th barnacles (Balanus spp. 1, scorched mussel (Brachlodontes exustus), r lbbed mussel (Geukensla dem) and J lng le she1 I (Anmla s f ) . The d l s t r l b u t l o n of 1 n t e r t l da l oysters does not appear t o be af fected by these organlrns (Dame 1970).

ENV 1 RONMENTAL REQU 1 REMENTS

The eastern oyster I s a very successf u l estuar 1 ne an 1 ma1 and, as such, It to le ra tes wldely varylng sal 1 n l t l es , temperatures, currents and t u r b l d l t l e s (Andrews 1979). The 1 n t e r t l dal oyster t h r lves I n t he most r igorous of hab i ta ts (Lunz 1960). To1 erance t o extremes o f one env 1 ronmental cond 1 t l o n I s o f ten modlf led by ln te rac t lon of another condi t ion such as an oyster 's ab l l l t y t o survive low sal l n l t y I n co ld weather (Andrews e t al . 1959). It Is, therefore, d l f f l c u l t t o prec ise ly def lne env Ironmental requlrements.

As a general ru le , C. requ l r e s temperatures above 19.5"C f o r egg development. Larvae develop p r o p e r l y above 20 OC and a d u l t s grow a t temperatures 10 t o 30 O C o r h ighe r ( G a l t s o f f 1964; B u r r e l l 1985b). Southern l n t e r t l d a l oys te rs a r e a b l e t o w i ths tand summer temperatures above 43 O C when exposed t o t he sun and then sudden drops t o 26 O C when the t i d e agaln covers t h e bed (Lunz 1960). Oysters a r e a l s o exposed t o w ln te r a i r temperatures t h a t may fa1 I be1 ow f reezlng; even when these oys te rs a r e exposed several hours t o these extremes, they apparent ly t o l e r a t e them we1 I. However, morta l I t y I n several oys te r beds I n t h e McCl e l 1 anvi 11 e, South Carol i na , area was almost 100% when a i r temperatures sudden1 y dropped 19 "C I n 24 h a f t e r several weeks o f above normal r a l n f a l I (Purv I s 1983). The 1982 c o l d wave was t h e most severe f o r December I n South Carol 1 na's h ls to ry , b u t lower than normal sal 1 n l t y caused by heavy r a l n f a l l may a l s o have been a c o n t r l b u t l n g f a c t o r t o t h I s morta l 1 t y . Oyster growers I n t h e area repo r ted deaths frm f r e e z l n g were most unusual I n these beds.

Castagna and Chanley (1973) I n a review o f sal l n l t y requlrements f o r I l f e stages o f oys te rs repo r ted t h a t egg cleavage occurred a t 7.5 t o 35 p p t w i t h opt imal development a t 10 t o 22 ppt, larvae developed a t 5 t o 39 ppt, and growth was bes t a t 25 t o 29 ppt. Metamorphosls occurred between 5.6 and 35 ppt. Spat grew bes t a t s a l l n l t l e s o f 15 t o 26 p p t (Chanley 1957). Adu l t oys te rs were produced commercl a l l y I n F l o r i d a I n areas where t h e s a l l n l t y v a r l e d from 0 t o 42.5 p p t ( I n g l e and Dawson 1950). Growth I s most f avo rab le a t 14 t o 30 p p t (Castagna and Chanley 1973).

Heavy r a l n s I n t h e watersheds o f r i v e r s feedlng e s t u a r l e s may on

occas Ion cause ca tas t roph l c k I l I s. Th I s may be assocl a ted w 1 t h t r o p l c a l storms o r h lgher than usual spr l ng r a l n s (Andrews e t a l . 1959; May 1972; Haven e t a l . 1976; Bu r re l l 1977). l n t e r t l d a l oys te rs I n t h e South Santee Rlver , South Carol lna, s u f f e r e d h lgher losses as a consequence o f low sal l n l t y than d i d sub t l da l oys te rs I n t h e same system. Th l s would be expected because sur face water would tend t o be l ess sal lne than bottom water and l n t e r t l d a l oys te rs would be subJect t o f reshe r water f o r a longer per lod. However, morta l l t l e s among s u b t l dal and l n t e r t l dal oys te rs were near I d e n t i c a l I n an adJacent estuary a t t h e same t ime (Bur re l l 1977). Oysters d led from lack o f oxygen I n t h e James Rlver, V l r g l n l a , I n w l n t e r and e a r l y s p r l n g 1979-80 because f reshwater cover ing t h e beds prevented t h e anlmals from feed lng and r e s p l r l n g (Andrews 1982). Th l s appears t o be a f a i r l y r e g u l a r phenmenon I n t h e Rappahannock Rlver, V l r g l n l a , I n wet years (Haven e t a l . 1976; Andrews 1982). Moderate s a l l n l t l e s ( those l ess than 15 p p t ) f o r a s l g n l f l c a n t per lod dur l ng t h e year may be benef l c l a l I n t h a t most p redators a r e excluded o r t h e l r numbers g r e a t l y reduced and sane dlsease organisms a r e kep t o u t o r t h e l r v i r u l e n c e I s markedly weakened I n these areas (Haven e t a l . 1978; Bur re l I e t a l . 1981 1 .

Oysters a r e to1 e r a n t o f low d l sso l ved oxygen, surv l v 1 ng a t concen t ra t i ons as low as 1 ppm (Andrews 1982). I n l aboratory studles, l a r vae ceased t o swlm and d led a f t e r 3 days when oxygen concen t ra t l on was 0.1 ppm and young spa t d led w i t h i n a week; however, a d u l t oys te rs surv lved much longer a t t h e same concen t ra t l on (Haven e t a l . 1978). Hour ly oxygen uptake I s low I n oysters, 15.5 cc/kg dry w t . , as would be expected f o r a sedentary anlmal (N l co l 1960). Furthermore, oys te rs probably use l ess than 1% o f t h e

oxygen ava i lab le I n the feedlng currents passing over t h e i r g i l l s (Gal t s o f f 1964).

The prefer red hab l t a t f o r oysters I n t h e South A t l a n t l c region I s f r a n j u s t be1 ow t he mean low water l eve1 t o about 1 m above mean low water (Sandlfer e t a l . 1980). I f a l l other condl t lons a re sui table, a f l r m bot tan I s no t necessary f o r a reef t o become establ lshed. A few oysters may at tach t o a b i t of she l l o r wood i n a mud- f l a t , and other oysters a t tach t o them, push lng them l n t o t h e mud and smother I ng them bu t prov I d I ng subst ra te f o r subsequent spat. Th I s process continues unt I l the f l r s t set, long s l nce dead, s l nks deep enough l n t o the mud t o reach a s u f f l c l e n t l y f l r m stratum t o prevent f u r t he r subsidence. Shel I s growing on top o f t h e bur led she1 l reach t h e surface o f t he mud and provlde attachment area f o r subsequent crops o f oysters. The reef then expands frm t h I s beglnnlng. The under ly lng mat r l x supporting ree fs I s f a l r l y f r a g l l e I n places and I t s I n t e g r i t y can be damaged by heavy harvest l ng gear. Water cur rents must be strong enough t o provlde food. (Ga l tso f f (1964) estimated t h a t water pass1 ng over an oyster reef shout d be renewed 72 tlmes I n a 24-h perlod. Also, cu r ren ts must wash away sediments and blodeposl ts o f anlmals lnhab l t l ng t he

ree f (Haven and Morales-Alamo 1 x 6 ) . Currents o f t o o great a vel o c l t y can I n te r f e re w l t h feedlng and cause s t ruc tu ra l damage (Gal t so f f 1964). P lan t lng she1 l t o establ lsh an I n t e r t l d a l oyster reef can be a f u t I l e exerclse I n many cases because t he she1 l may serve as a baf f l e I n t h e cu r ren t and c o l l e c t sedlment and t h a t r e s u l t s I n r ap id s i l t i n g over (Smith 1949).

Fnv l w a l FactpIls

A f a l r l y large t l d a l range Increases the I n t e r t i d a l area I n the South A t l ant l c States because of l l t t l e re1 l e f I n coastal areas. Thls t i d e range I s from about 1.5 t o 2.1 m. These t l des provlde a mechanism f o r f l u sh lng adjacent marsh areas and enr lch lng t he oyster-growing water (Manzl e t a l . 1977). Because t u r b l d l t y I s h igh I n southern estuaries, phytoplankton productlon I s canparat lvely low; consequently marsh con t r l bu t lon t o oyster nu t r l t l o n I s probably much more Important here (Manzl e t a l . 1977).

Oysters, wh l l e to1 erant o f f a l r l y t u r b l d water, decrease pumplng r a t e w l t h Increase I n s l l t concentrations above 1.0 g / l and death may occur a f t e r 1 ong-term exposure. Egg surv lva l was on ly 73% I n water wl th a s l l t concentrat lon o f 0.25 g/ l , and a t 0.75 g / l growth of larvae was s lgn 1 f l can t l y a f fec ted (Loosanof f and Tanmers 1948; Loosanof f 1962).

L I TERATURE C 1 TED

Abbott, R.T. 1974. Amer I can seashells. The marine Mollusca of the A t l a n t l c and Paclf l c coasts o f North America. Van Nostrand Relnhold Co., New York.

Anderson, W.D., 1 1 1. 1976. A canparatlve study of a s a l t water Impoundment w l t h I t s adJacent t l d a l creek per ta ln lng t o cu l t u re of Crassostrea d . , c g h b ( h e 1 In). M. S. Thesls. Old Dmln lon Unlverslty, Norfolk, V l rg ln la . 65 PP-

Andrews, J.D. 1979. Pel ecypoda: Ostreldae. Pages 293-341 In A.C. GIese and J.S. Pearse, eds. Reproduction of mar 1 ne 1 nvertebrates. Vol . 5: Mol I uscs: Pel ecypoda and I esser c l asses. Academic Press, New York.

Andrews, J.D. 1982. Anaerobic mortal l t l e s of oysters I n V l r g l n l a caused by low sal l n l t l e s . J. Shel l f lsh Res. 2(2): 127-132.

Andrews, J.D., D.S. Haven, and D.B. Quayle. 1959. Freshwater k l l l of oysters, Crassostrea y-h, I n James Rlver, V l rg ln la . Proc. Natl. Shel l f lsh. Assoc. 49: 29-49.

Bahr, L.M. 1974. Aspects o f t he s t ruc tu re and funct lon of the I n t e r t i d a l oyster reef communlty I n Georgl a. Ph.D. D lsser ta t Ion. Un I vers I t y o f Georg I a, Athens.

Bahr, L.M., and W.P. Lanler. 1981. The ecol ogy of I n t e r t l dal oyster ree fs of t he South A t l a n t l c coast: a communlty p ro f l l e . U.S. Flsh Wlldl . Serv., B lo l . Serv. Program, Wash, D.C. FWS/OBS 81/15. 105 pp.

Batt le, J.D. 1892. An lnvest lgat lon of coastal waters o f South Carol I na w i t h reference t o oyster cu l ture. U.S. Fish. Canm. Bul l . No. 10: 303-330.

Burrel I, V.G., Jr. 1977. Mortal l t l e s of oysters and hard clams associated w i t h heavy runof f I n t he Santee Rlver system, South Carol lna I n the spr lng o f 1975. Proc. Natl . Shel l f lsh. Assoc. 67: 35-43.

Burrel I, V.G., Jr. 1982. Overv lew of t he South A t l an t l c oyster Industry. Proceedings of t he North Amerlcan Oyster Workshop. Wor l d Mar I c. Soc. Spec. Publ . No. 1: 125-127.

Burrel I, V.G., Jr. 1985a. Mol luscan f lsher les of t he South A t l an t l c reg Ion of t he Un l t ed States. Natl . Shel I f lsh. Assoc. Annu. Meet. Abstrs. p. 25.

Burrel I, V.G., Jr. 1985b. Oyster cu l ture. Pages 235-273 In J.V. Huner and E.E. Brown, eds. Crustacean and mol l usk aquacu l t u r e I n t he Unlted States. A V I Publ. Co., Westport, Conn.

Burrel I, V.G., Jr., M.Y. Bobo, and J.J. Manzl. 1984. A comparison of seasonal l n c l dence and lntens lty of P a mchis between subt ldal and I n t e r t 1 da l oyster popu l a t Ions I n South Carollna. J. World Marlcul. SOC. 15: 301-309.

Burrel I, V.G., Jr., J. J. Manz I, and W.Z. Carson. 1981. Growth and mortal l t y of two types of seed oysters f r an the Wando Rlver, South Carolina. J. She l l f l sh Res. l ( 1 ) : 1-7.

Cake, E.W., Jr. 1983. Hab l ta t su l t ab l l l t y Index models: Gul f o f Mexlco Amerlcan o ster. U.S. F lsh Wl ld l . Serv. FWS~OBS-82b0.57. 37 PP*

Carrlker, M.R. 1951. Ecological observatlons on the d l s t r 1 but lon o f oyster larvae I n New Jersey estuarles. Ecol. Monogr. 21(1): 19-38.

Carrlker, M.R. 1955. C r i t i c a l revlew of biology and cont ro l o f oyster d r l l l s l h d - ~ h x and h ~ h l ~ ~ . U.S. Flsh. Wi ld l . Serv. Spec. Scl. Rep. Flsh. 148. 150 pp.

Castagna, M., and P. Chanley. 1973. Sal l n l t y to lerance of some mar lne b l va l ves f rm 1 nshore and estuar 1 ne environments I n V l r g l n l a waters on t h e western mid-Atl a n t l c coast. Malacologla 12(1): 47-96.

Chanley, P.E. 1957. Survival o f sane Juvenile blvalves I n water o f low sal l n l t y . Proc. Natl. Shel 1 f l sh . Assoc. 48: 52-65.

Chestnut, A.F., and W.E. Fahy. 1953. Studies on the v e r t l c a l d l s t r l but lon o f s e t t i n g o f oysters I n North Carol Ina. Proc. Gulf Carlbb. Flsh. Inst. 5: 106-112.

Cowman, C.F., Jr. 1982. A b r l e f ana lys ls o f Georgl a's oyster Industry. Proc. North Amer lcan Oyster Workshop. Wor l d Mar lc. Soc. Spec. Publ. No. 1: 128-131.

Dame, R.F. 1970. The ecologlcal energles of growth, r esp l r a t l on and asslrnl l a t l o n I n t h e l n t e r t l d a l Amr I can oyster, - viralnica (Gmel In) . Ph. D. Dl ssertat lon. Unlversl t y o f South Carol lna, Columbia.

Dame, R.F. 1972. The ecologlcal energles of growth, resp l ra t lon, and asslml l a t l o n I n t h e l n t e r t l d a l Amer 1 can oyster Crassostrea &aInlca. Mar. B lo l . 17: 243-250.

Dame, R.F. 1979. The abundance, d lvers l t y and b fomass o f macrobenthos on North I n l et, South Carol lna, l n t e r t l d a l oyster reefs. Proc. Natl. Shel l f lsh . Assoc. 69: 6-10.

Dean, B. 1892. The physical and b lo log l ca l character l s t l c s of natural oyster grounds of South Carol lna. Bul I. U.S. Flsh. Canm. 10: 335-362.

De l a Cruz, A.A. 1973. The r o l e o f t l d a l marshes In p roduc t l v l t y o f coastal waters. Assoc. Southeast. B l o l . Bul I. 20(4): 147-1 56.

Dupuy, J. L., N. T. W l ndsor, and C. E. Sutton. 1977. Manual f o r deslgn and operat ion of an oyster hatchery. Va. Inst . Mar. Scl. Spec. Rep. Appl. Mar. Scl. Ocean. Eng. No. 142. 104 pp.

Durant, J.E. 1969. The e f f e c t s o f temperature and sal 1 n l t y upon the gonadal cyc le o f Crassostrea

(Gmelln) I n Georgla waters. Pages 132-144 la T.L. Llnton, ed. Feas ib l l lty study of methods f o r 1 mprov 1 ng oyster production I n Georgla. Compl. Rep. ProJ. 2-10-R. Bur. Comrn. Flsh. P.L. 88-309.

Galtsoff, P.S. 1964. The Amerlcan oyster, Crassosirea - Gmel In. U.S. Flsh. Wl ld l . Serv. Flsh. Bul I. 64. 480 pp.

Galtsof f , P.S., and A.S. M e r r l l l . 1962. Notes on she1 1 morphology, growth and d l s t r l bu t Ion o f

Say. Bul I. Mar. Scl. Gul f Car lbb. 12(2): 234-244.

G I l lmor, R.B. 1982. Assessment o f 1 n t e r t l d a l growth and capaclty adaptlons In suspension-feedlng b lva l ves. Mar. B lo l . 68(3): 277-286.

Hask I ns, H. H. 1964. The d l s t r 1 bu t I on of oyster larvae. Pages 76-80 la

N. Marshal I, ed. Proc. Symp. Exp. Mar. Ecol. Rhode I s land (USA), Occas. Publ. No. 2: Narraganset t Mar. Lab, Grad. School Oceanog., Unlv. R.I.

Haven, D.S., and V.G. Bur re l I, J r . 1982. The oyster...a s h e l l f i s h del i cacy. Marine Resources o f t h e A t l a n t i c coast, 2nd ed. A t l a n t l c States Mar. Fish. Comm. Lea f l . 11. 8 PP-

Haven, D.S., and R. Moral es-A1 amo. 1966. Aspects o f b lodepos l t l on by oys te rs and o the r 1 nve r teb ra te f 1 l t e r feeders. L lmnol . Oceanogr. 1 1 ( 4 ) : 487-498.

Haven, D. S., and R. Moral es-AI amo. 1970. F l l t r a t l o n o f particles from suspension by t h e Arner lcan oyster, Crassost rea v l r a l n i c a . B l o l . Bul I. (Woods Hole) 139(2): 248-264.

Haven, D. S., W. J . Harg 1 s, Jr., and P.C. Kendal 1 . 1978. The oys te r Indust ry o f V l r g l n l a : I t s s tatus, prob l ems and pr an I se, a comprehens I ve study o f t h e oys te r lndus t ry I n V l r g l n i a . Va. I ns t . Mar. Scl. Spec. Pap. Mar. Scl. No. 4. 1025 pp.

Haven, D.S., W.J. Hargis, Jr., J.G. Loesch, and J.F. Whltcanb. 1976. Shel 1 f 1 sh emergency rehab i l 1 t a t 1 on program. Va. I ns t . Mar. Scl. Va. Mar. Resour. Comm. Compl . Rep. Mar. 1974-1975. 65 pp.

Hldu, H., and H.H. Hasklns. 1971. S e t t l n g o f t h e Amerlcan oys te r re1 a ted t o env lronmental f a c t o r s and l a r v a l behav l o r . Proc. Nat l . Shel l f l s h . Assoc. 61: 35-50.

Ingle, R.M. 1950. Summer growth of t h e Amerlcan o y s t e r I n F I o r I d a waters. Sclence 1 12(2908) : 338-339.

Ingle, R.M. 1951. Spawnlng and s e t t l n g o f oys te rs I n r e i a t l o n t o seasonal env 1 ronmental changes. Bul I. Mar. Scl. Gu l f Carlbb. 1(2) : 11 1-135.

Ingle, R.M., and C.E. Dawson, Jr . 1950. V a r l a t l o n i n s a l l n l t y and I t s re1 a t l o n t o t h e F l o r i d a oyster . Sal l n l t y v a r l a t l o n I n Apalachlcola Bay. Proc. Nat l . Shellfish. Assoc. 16-19.

Kel th, W.J., and R.C. Gracy. 1972. H i s t o r y o f t h e South Carol lna oyster . S.C. W i ld l . Mar. Resour. Dep. Mar. Resour. Dlv. Ed. Rep. 1. 19 PP*

L lnton, T.L. 1969. Inventory of l n t e r t l d a l oys te r resources o f Georgla. Pages 5-21 In T.L. Linton, ed. F e a s l b l l l t y study o f methods f o r lmprov ing oys te r product Ion l n Georgla. Canpl. Rep. ProJ. 2-10-R. Bur. Comm. Flsh. P.L. 88-309.

Loosanoff, V.L. 1962. E f f e c t s o f t u r b l d l t y on sane l a r v a l and a d u l t b lvalves. Proc. Gul f Carlbb. Flsh. I ns t . 14: 80-95.

Loosanoff, V.L. 1969. Maturation of gonads o f oysters, b s o s t r a a -, of d 1 f f e r e n t geograph 1 ca l areas sub jec ted t o r e l a t l v e l y low temperatures. Vel l ge r 11 (3 ) : 153-163.

Loosanoff, V.L., and F.D. Tmmers. 1948. E f f e c t o f suspended s l l t and o t h e r substances on r a t e o f feed lng In oysters. Sclence 107: 69-70.

Lunz, G.R., Jr . 1941. -,a pes t I n South Carol lna oysters. J. E l l sha Ml tche l l Scl. Soc. 57(2): 273-283.

Lunz, G.R., Jr . 1943. The y l e l d o f c e r t a l n oys te r landlngs I n South Carol Ina. h e r . Mld l . Nat. 30(3) : 806-808.

Lunz, G.R., Jr. 1947. versus "Ostrea. n J. El lsha Mltchel I Scl. Soc. 63(1): 81.

Lunz, G.R., Jr. 1950. Production and y l e l d o f the oyster cannl ng Industry o f South Carol lna. Contr l b. Bears B l u f f Lab, No. 9. 14 pp.

Lunz, G.R., Jr . 1955. Cu l t l va t l on o f oysters I n ponds a t Bears BI u f f Laborator les. Proc. Natl. Shel l f lsh. Assoc. 46: 83-87.

Lunz, G.R., Jr. 1960. I n t e r t i d a l oysters. Wards Nat. Sc I. Bul I. 34(1): 3-7.

Lutz, R.A., H. Hldu, and K.G. Drobeck. 1970. Acute temperature Increase as a stimulus t o s e t t l n g I n the h e r I can oyster, Crassostrea m. Proc. Natl. Shel I f lsh. Assoc. 60: 68-71.

Magglonl, G.J., and V.G. Burre l l , Jr. 1982. South Carol Ina oyster Industry. Proceedl ngs o f North Amer I can Oyster Workshop. Wor I d Marlc. Soc. Spec. Publ . No. 1: 132-137.

Manz I, J. J., V.G. Burrel I, Jr., and W.Z. Carson. 1977. A canpar lson of growth and survlval of subt ldal Crassostrea (Gmel In ) I n South Carol Ina s a l t marsh Impoundments. Aquaculture 12: 293-3 1 0.

Manzl, J.J., V.G. Burre l l , Jr., K.J. Klemanonlcz, N.H. Hadley, and J.A. Co l l i e r . 1985. Impacts of a mechanical harvester I n I n t e r t i d a l oyster communltles I n South Carol Ina. Flnal Report. Coastal Energy Impact Program, Off Ice o f the Governor, Col unbla, S.C. 31 pp.

May, E.B. 1972. The e f f e c t of f loodwater on oysters In the Mob l l e Bay. Proc. Natl. Shel l f lsh. Assoc. 62: 67-71.

McKenzle, C.L., Jr. 1981. B i o t i c potent I a l and env 1 ronmental resistance I n t h e Arner Ican oyster (Crassostrea d-cgfnlca) I n Long l s l and Sound. Aquacul t u r e 22: 229-268.

McNulty, J.K. 1953. Seasonal and ve r t i ca l patterns o f oyster s e t t lng o f f Wadmalaw Island, S.C. Contrlb. Bears Bl u f f Lab. No. 15. 17 pp.

Menzel, R.W. 1956. Sane addi t ional d i f ferences between Crassostrea - a n d D i l a squstrIs I n t he Gulf o f Mexlco. Proc. Natl. Shel l f lsh. Assoc. 46: 76-82.

Merrlner, J.V., and J.W. Smith. 1979. A r epo r t t o t he oyster Industry o f V l r g l n l a on the blology and management o f t he connose ray (&dmptem ltfuusu MlJchl l l ) I n lower Chesapeake Bay. Va. Inst. Mar. Scl. Spec. Rep. Appl . Mar. Scl . Ocean Eng. No. 216. 33 pp.

Moore, C. J., H. M I l Is, and D. Cupka. 1984. Recreat lonal she1 l f l sh gather lng I n South Carol I na 1980-81. S.C. Wl ldl . Mar. Resour. Dep. S.C. Mar. Resour. Cent. Tech. Rep. No. 37. 9 pp.

Munden, F.H. 1982. A rev lew of t he North Carol lna oyster rehab 1 l l t a t l o n progrm. Proceed1 ngs o f t he North Amer Ican Oyster Workshop. Wor I d Marlc. Soc. Spec. Publ. No. 1: 138-151.

Nelson, T.C. 1925. On the occurrence and food hab i ts of ctenophores I n New Jersey Inland coastal waters. B lo l . Bu l l . 48: 92-111.

Nlcol, J.A.C. 1960. The biology o f marine animals. Pltman House, London, U.K. 707 pp.

Palmer, B.A. 1976. Coastal f lsher les oyster research (second annual repor t ) . Georg l a Department o f Natural Resources, Game and Fish

Dlv lslon, Coastal F l sher les O f f 1 ce. Par t 1 1. 14 pp.

Porter, H. J., and J. Tyler. 1974. Seashel I s canmon t o North Carol lna. N.C. Dep. Nat. Econ. Res. Dlv. Canm. Sportf Ish. Inf . Ser. 36 pp.

Purv Is, J. C. 1983. CI Imatol oglcal data. South Carol Ina, Decmber. Dep. Comm. NOAA. Natl. CI lmatIc Data Center, Ashev l l le, N.C. 1983 (12): 1-19.

Re1 s l nger, E.A., Jr. 1978. Demonstrate r e v l t a l l za t ion of oyster beds by resur fac l ng and reseed1 ng. Fourth quarter r epo r t and sunmatlon of f i f t h year's work 1977-1978. Coastal P la ins Regional Canmlsslon, Charleston, S.C. 25 pp.

Sandlfer, P.A., J.V. Mlglarese, D.R. Cal der, J. J. Manz 1, and L.A. Barcl ay, eds. 1980. Ecological character l za t l on of t he sea Is1 and coastal reg Ion of South Carol I na and Georg 1 a. Vol. 3: B lo log lca l features of the character l za t lon area. U.S. Flsh Wlldl . Serv. B lo l . Serv. Program. FWS/CBS-79/42. 620 PP*

Sel Iers, M.A., and J.G. Stanley. 1984. Species prof 1 les: l 1 f e h l s t o r les and env 1 ronmental requirements of coastal f lshes and Invertebrates (North A t l an t i c ) -- American oyster. U.S. Fish. Wlldl. Serv. FWS/CBS-82/11.23. U. S. Army Corps of Engl neers, TR EL-82-4. 15 PP-

Smlth, R.0. 1949. Summary of oyster farming exper lments I n S.C. 1939-1940. U.S. Flsh Wlldl . Serv. Spec. Scl. Rep. No. 63. 20 pp.

Wel Is, H.W. 1961. The fauna of oyster beds, w l t h spec1 a1 reference t o t he saI l n l t y factor. Ecol. Monogr. 31(3): 239-266.

Wood, L., and W.J. Hargls, Jr. 1971. Transport of b iva lve larvae I n a t 1 dal estuary. Pages 29-44 In D. J . Crlsp, ed. Marlne blology. Fourth European Symposl um. Cambr I dge Unlvers l ty Press.

Yonge, C. M. 1960. Oysters. W I I l mer Brothers and Haram, Ltd. London. 209 pp.

REPORT DOCUMENTATION 1. 2.

PAGE / B i o l o a i c a l Renor t 8 2 ( 1 1 . 5 7 d 4. ntl. a d suot~t~.

Species P r o f i l e s : L i f e H i s t o r i e s and Envi ronmenta l Requi rements o f Coasta l F ishes and I n v e r t e b r a t e s (South At1 a n t i c ) -- A o e r i can Oys te r

7. Authods) 8. Parlormtna Or#an#ration Rapt. No.

V i c t o r G. B u r r e l 1, J r . b. Parformin# O~anlzat ion Narna and Addrass

11. Contract(C) or Gran#C) No. I- 1 12. Smnsorin# Orasnlzatlon Nama rnd Addrasn

Nat iona l Wetlanas Research Center U.S. Army Corps o f Engineers F i s h and W i l d l i f e S e r v i c e L4aterv1ays Exner iment S t a t i o n U.S. Denar tnent o f the I n t e r i o r P . 0. Box 631 Washington, DC 20240 Vicksburg, ?IS 39180

1% Supplamanta~ Notas

*U.S. Army Coros o f Enqineers Repor t No. TR EL-82-4 lh Abstrmcl (Llrnll: 200 words) Species p r o f i l e s a r e 1 i t e r a t u r e summaries o f t h e taxonomy, morphology, range, 1 i f e h i s t o r y and envi ronmenta l requi rements o f c o a s t a l soecies. They a r e des igned t o a s s i s t i n env i ronmenta l impact assessment. The American o y s t e r , Crassos t rea v i r g i n i c a , i s an i m n o r t a n t commercial and r e c r e a t i o n a l species. Snaivning cccurs c o n t i n u o u s l y i n warmer months. Larvae a r e p l a n k t o n i c and a r e d i s t r i b u t e d t h r o u ~ h o u t e s t u a r i e s by t i d a l c u r r e n t s . A f t e r a 2- t o 3-week n l a n k t o n i c s tage, l a r v a e nermanent ly a t t a c h t o a s o l i d s u b s t r a t e . I n t h e South A t l a n t i c r e g i o n , t h i s s o l i d s u b s t r a t e i s u s u a l l y t h e s h e l l o f o t h e r o y s t e r s growing i n t h e i n t e r t i d a l zone. T h i s g r e g a r i o u s b e h a v i o r r e s u l t s i n f o r m a t i o n o f massive i n t e r t i d a l r e e f s t h a t a r e a prominent f e a t u r e o f h i g h s a l i n i t y bays, creeks and sounds i n t h e reg ion . These r e e f s se rve as h a b i t a t and f o r a q i n g grounds f o r o t h e r snecies. Oys te rs t o l e r a t e s a l i n i t y f rom about 5 p n t t o above 40 n ~ t and temperatures f rom below f r e e z i n g t o n e a r l y 50°C.

E s t u a r i e s L i f e c y c l e s Oxygen Oysters Feeding h a b i t s Suspended sediments Growth Temperature Feedi ng S a l i n i t y

b. Idantlfian/Ovan.Cndad Iarms I American o y s t e r Temoerature r e a u i rements ~ r a s s o s t r e a v i r g i n i ca Spawning S a l i n i t y requi rements

C. COSAIl Field/Gmup

1h Avallabllity Statamsnt

Unl i m i t e d Re1 ease

(Saa ANS1-239.10 OPTIONAL FORM 272 (4-7 (Fornwrly W T I E 3 8 Drpaarnant d Commerca

19. Security Class Vhis RewdJ

U n c l a s s i f i e d ZU. Security C I ~ S S Vhis pace)

U n c l a s s i f i e d

21. No. of Pnacs

17 -- a. price

REGION 1 REGION 2 REGION 3 Regional Director Regional Director Regional Director U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service Lloyd Five Hundred Building, Suite 1692 P.O. Box 1306 Federal Building, Fort Snelling 500 N.E. Multnornah Street Albuquerque, New Mexico 87 103 Twin Cities, Minnesota 55 1 1 1 Portland, Oregon 97232

REGION 4 Regional Director U.S. Fish and Wildlife Service Richard B. Russell Building 75 Spring Street, S.W. Atlanta, Georgia 30303

REGION 5 REGION 6 Regional Director Regional Director U.S. Fish and Wildlife Service U.S. Fish and Wildlife Service One Gateway Center P.O. Box 25486 Newton Corner, Massachusetts 02158 Denver Federal Center

Denver, Colorado 80225

REGION 7 Regional Director U.S. Fish and Wildlife Service 101 1 E. Tudor Road Anchorage, Alaska 99503

TAKE PRIDE 212 Amerzcd

DEPARTMENT OF THE INTERIOR U.S. FISH AND WILDLIFE SERVICE

As the Nation's principal conservation agency. the Department of the Interior has respon- sibility for most of our .nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving thsenvironmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department as- sesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration.