1. Secondary Production of Infaunal Benthic Communities in Chesapeake Bay in Comparison to Restored Oyster Reefs
Amanda Lawless and Dr. Rochelle Seitz
Virginia Institute of Marine Science,
The College of William & Mary
Gloucester Point, VA

2. Introduction Eastern Oyster, Crassostrea virginica
Ecologically and commercially important in Chesapeake Bay
Over-harvesting, disease, pollution, and loss of habitat have drastically reduced the population
Reef restoration
Chesapeake Bay Oyster Harvest (’53-’98)

3. Chesapeake Bay
Lynnhaven Bay

4. Lynnhaven Bay Characteristics: Shallow Tidal Influence
Temperature: 26-32°C
Salinity: ppt
Chesapeake Bay
Lynnhaven River
Atlantic Ocean
Western Branch
Eastern Branch
Broad Bay
Linkhorn Bay

5. Objective
To compare the productivity of a lost benthic community to the productivity of oysters on four types of oyster reefs

6. Oyster Reefs
Oyster Shell Reef
Module Reef
Rip Rap Reef
Reef Ball

7. Methods Benthic Sampling Bivalves Remaining Infauna
Macrofaunal suction (0.11 m area to 40 cm depth)
Four random samples, prior to reef deployment
Bivalves
Macoma balthica
Tagelus plebeius
Remaining Infauna
Estimated from previous samples in the Bay
(Dauer 2000, 2002 sampling of Elizabeth River)

8. Calculations - Benthos
Total Infaunal Biomass (g AFDW m-2)
Bivalves – est. from length/weight regression
Remaining Infauna
(Dauer 2000, 2002 sampling of Elizabeth River)
Multiply by a range of published P:B
(Diaz and Schaffner 1990; Baird and Ulanowicz 1989)
Production of benthos (g AFDW m-2/yr)
Multiply by area of benthos lost per reef type (g AFDW/yr)

9. Calculations - Oysters
Biomass of oysters (g AFDW m-2)
Oyster shell – Fishermen’s Island, lower Bay
O’Beirn et al. 1999
Modules – Rappahannock River
Lipcius and Burke 2006
Rip rap – Lynnhaven system
Burke (in progress)
Reef balls – 90% module and 10% shell
Multiply by a published P:B
Dame 1976; Bahr and Lanier 1981
Production of oysters (g AFDW m-2/yr)
Multiply by area available for settlement per reef type (g AFDW/yr)

10. Remaining Infauna Biomass
Results - Benthos
Site
Bivalve Biomass
(g AFDW m-2)
Remaining Infauna Biomass
P:B
Production
(g AFDW m-2/yr)
Eastern Branch
19.66
0.931
59.7 – 158.6
Linkhorn
9.73
30.9 – 36.9

11. Results – Oysters Reef Type Biomass (g AFDW m-2) P:B Production
(g AFDW m-2/yr)
Area
(m2)
Total Production
(g AFDW/yr)
Oyster
Shell
600
2.4
1440
0.656
945 * 3 = 2,835
Rip Rap
45.4
109
71.5 * 3 = 214.5
Module
13.7
32.9
4.3
141.5 * 3 = 424.5
Reef Ball
72.3
173.5
416.4 * 3 = 1,249

12. Benthos vs. Oysters
2,835
63%
55%

13. Conclusions
All reef types compensated for the lost benthic production at the site with lower productivity
Oyster shell and reef ball reefs compensated for the lost benthic production at the higher productivity site; however, the rip rap and module reefs may not compensate
Revisit the sites in the future
Obtain actual oyster production values for the four reef types at each site
Revaluate
Important to characterize the benthic community prior to reef deployment
Determine the best type of reef for a particular area

14. Acknowledgements Dr. Rochelle Seitz, VIMS Dr. Rom Lipcius, VIMS
Community Ecology Group, VIMS
Marine Conservation Biology Group, VIMS
Chesapeake Bay Foundation
US Army Corps of Engineers, Norfolk, VA Office
NOAA Chesapeake Bay Office