Oyster Restoration & Research in Virginia: Some Metrics & How … · 2012-06-06 · Oyster Restoration & Research in Virginia: Some Metrics & How We Monitor Them P.G. Ross College

Oyster Restoration & Research in Virginia:

Some Metrics & How We Monitor Them

P.G. RossCollege of William and Mary

VA Institute of Marine ScienceEastern Shore Laboratory

Oyster Restoration WorkshopMyrtle Beach, SCMay 20-21, 2004

Restoration Projects

Now over 100 “restoration” sites in Virginia

Research Projects

NOAA, ACOE

VEE, VORHF, NOAA

NOAA Sea Grant

EPA-CBP

Research Funded By

Yes (proposed)

Possibly, brood stock

Possibly, brood stock

Yes, cultch

Adaptive Mgt.

VMRC1VA, ACOE Others

Oyster Heritage (2003-current)

VMRC1VA, ACOE Others

Army Corp. Project (2004-

current)

VMRC1ACOERappahannock River (2000-2002)

VMRC1CBBT, VA

Power, VMRC

Fisherman’s Island (1996-1999)

Built ByConstruction Funded ByProject

1 Built on sites chosen by and under the supervision of VMRC by commercial sub-contractors

Research Projects

400-8000 m2

400-8000 m2

100-500 m2

Scale

Sub

Sub

Inter

Ht.

64

10

13

# Reefs

64

4

1

# Sites

Monitoring biological &

physical parameters

Habitat/Brood stock4-11

OHP(‘03-’04) ACOE(‘04-)

Scale (landscape &

reef size), architecture

Habitat/Brood stock4Rapp.

(‘01-’02)

Community structure,

architecture Mitigation8FI

(‘96-’99)

Research Priorities

Restoration Purpose

Age (yrs)Project

Opportunistically utilize existing or planned reefs for larger scale research…

2 reefs

Now over 100 “restoration” sites in VirginiaGreat Wicomico RiverSalinity ~ 16 pptTide ~ 0.4 m

Rappahannock RiverSalinity ~ 15 pptTide ~ 0.5 m

Piankatank RiverSalinity ~ 16 pptTide ~ 0.4 m

Fisherman’s IslandSalinity ~ 30 pptTide ~1 m

Reef DesignTypical Marker Buoy

Individual Shell PilesFisherman’s Island

Rapp.

SEABED

REEF MOUND

WATER SURFACE (MLW)

~3 m

~1-2 mCrest

Flank

Base

Monitoring MethodsOyster Settlement

•Ceramic tiles, unglazed surface down • 5 cm above reef surface•Bi-weekly until settlement begins, then weekly

•Measure timing & intensity of recruitment

0

250

500

750

1000

1250

1500

5/17 6/7 6/28 7/19 8/9 8/30 9/20 10/11 11/1 11/22

Crane's CreekShell Bar

# O

yste

rs p

er m

2pe

r W

eek

Date

2003

•Diver collected substrate sample•25 x 25 cm to a depth of 10 cm•Intra-reef variation – replication•Spring, Summer & Fall

Epifaunal PopulationMonitoring Methods

•Determine oyster population status•ID species presence, richness, diversity•Develop trophic modelsOyster density, size & biomassEpifaunal diversity & trophic linksOyster sex ratioOyster female fecundityDisease prevalence & intensityGenotyping (DEBY vs. local strains)0

200

400

600

800

1000

Summer 2001 Fall 2001 Summer 20020

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

# •

m-2

(sol

id li

ne) H’ (dashed line)

Mean Epifaunal Abundance & Diversity (+/- SE)

Density, size & biomass

Sex ratio

Female fecundity

Disease prevalence & intensity

Genotyping

Monitoring MethodsOyster Population

0

100

200

300

400

500

600

CC SB BP PB DG PR

# O

yste

rs m

-2(+

/-SE

) May 2003

Reefs within Rappahannock

0

10

20

30

40

50

60

1 10 19 28 37 46 550

10

20

30

40

50

60

1 10 19 28 37 46 55

(A) Drumming Ground

Fall 2001 Summer 2002

# O

yste

rs p

er sa

mpl

e

Oyster Shell Ht. (1 mm intervals)

Monitoring MethodsOyster Mortality & Growth

•Remote settlement onto clean oyster shell•Manipulate density •Tether to frames•Deploy & recover during various seasons

•Estimate predation mortality•Indirectly measure food availability•Evaluate size specific groups

0

0.1

0.2

0.3

0.4

0.5

MC DG PR TB

2001-2002 Data Combined

Reef Site (Rappahannock Project)

% M

orta

lity•

Day

-1 (+

SE) A

B B B

Monitoring MethodsMotile Resident Community

•Bury baskets of reef material into reef matrix•Recover and capture organisms residing in baskets•6, 12 & 18 months post-deployment

•Species presence, richness, diversity •Develop trophic models

0.0

2.0

4.0

6.0

8.0

10.0

1 5 9 13 17 21 25 29 33 37 >40.5

Summer 2001

% X

anth

ids

Carapace Width, 1 mm intervals

Xanthid Size Frequency Distribution-Rapp. Project

0

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0 200 400 600 800 1000 1200

Xanthid Abundance (# • m2)Oys

ter

Mor

talit

y (%

•da

y-1)

P=0.0282R2=0.472

•Species presence & abundance, richness, diversity•Develop trophic models

Monitoring MethodsTransient Community

Gill netTrawlEncircling seineObservational

transectsUnderwater video

surveillance

38Naked Goby (Gobiosoma bosci)

5Spot (Leiostomus xanthurus)

8Striped Bass (Morone saxatilis)

18White Perch (Morone americanus)

29Croaker (Micropogonias undulatus)

36Menhaden (Brevoortia tyrranus)

4Feather Blenny (Hypsoblennius hentzi)

55Skilletfish (Gobiesox strumosus)

(%)Species (Resident and Transient Groups)

Relative abundance of dominant species (Rapp 2001-2002)

Monitoring MethodsPhysical Characteristics of Reef

3-D shape & bathymetryInterstitial spaceSurface rugosityParticle geometryLarge scale flow patternsTemporal changes…..?

•Determine static vs. dynamic nature of veneer•Physical parameters to correlate with biological parameters


Parrot’s Rock Bathymetry

Side Scan Sonar

-100 0 100 200 300 400 500 6000

100

200

300

400

500

Scale

25 cm/s

DISTANCE EAST (m)

DIS

TANC

E N

ORTH

(m)

ADV Stacked Flow Profile


245 mm

140 mm

Oyster Mortality-Interstitial Space

y = 526224 x-2.2699

R2 = 0.8948p = 0.0092

0

10

20

30

40

50

60

70

80

90

40 45 50 55 60 65 70

% Interstitial Space

% O

yste

r M

orta

lity

Monitoring Methods

Semi-annually (July & Oct.)Oyster disease & genotyping

Bi-weekly (May-Sept.)Oyster fecundity

Bi-weekly (June-Sept.)Plankton tows (larvae)

Quarterly (spring, summer & fall)Quadrates (epifauna & physical)

Bi-weekly/weekly (June-Oct.)Oyster settlement (tiles)

FrequencyTechnique

Techniques Planned for 2004

Current projects mainly focused on monitoring oyster population

Utilizing correlation analysis and regression to determine relationships

GraniteLimestone Marl

Surf Clam Shell

Demolished Cinder Block

Demolished Concrete

Alternative Substrates

Particle size, interstitial volume & surface

rugosity

“Lessons Learned”Location, location, location


Architecture can matter



Reef matrix may be dynamic for sub tidal reefs




Large scale H2O quality (anoxia) & weather (hurricane/rainfall) events can have impacts on success





Success criteria are likely variable regionally & locally –minimal natural standards for comparison






Measuring success at one point in time may be misleading-temporal trends may be more relevant






Measuring success at one point in time may be misleading-temporal trends may be more relevant

When and how we sample really matters

Oyster population growth +, or at higher densities, at least stable over several years

Multiple oyster size/age cohorts present over time

Overall community diversity increasing over time to stabilize after 3-5 years

Key community species (i.e. trophically) present in multiple age classes. Identify species/genera in multiple taxa that are indicative of healthy community

Does community equilibrate quickly (e.g. 2-3 years) after significant environmental perturbations

Some Criteria for Success

Measurement of these variables requires multiple years of monitoring (possibly 5+ years continuously). The challenge is to get financial

commitments to longer-term monitoring than is currently standard

Potential Hurricane Impacts??

0

50

100

150

200

250

300

350

400

S P R IN G 2003 SU M M ER 2003 FA LL 2003

SB BP D G

0

50

100

150

200

250

300

350

400

S P R IN G 2003 SU M M ER 2003 FA LL 2003

C C PB PR

A) Reefs with stable oyster abundance

B) Reefs with lower oyster abundance

Hurricane Isabell

Hurricane Isabell

# O

yste

rs m

-2

substrate

collar

Flux MeasurementsFlux Measurements

BiBi--monthlymonthlyApr Apr –– Oct:Oct:

DIN (NHDIN (NH44++, NO, NO22

--

NONO33--), ),

DODODIP (PODIP (PO44

33--))DONDONChl aChl a

160 Cages Deployed June 2003

Cages

Reef Schematic

Pala

ce B

ar R

eef

Documents

Oyster Restoration & Research in Virginia: Some Metrics & How … · 2012-06-06 · Oyster Restoration & Research in Virginia: Some Metrics & How We Monitor Them P.G. Ross College