1. Direct vs. indirect impacts of salinity on oyster (Crassostrea virginica) health and abundance Melanie L. Parker and William S. Arnold FWC - Fish & Wildlife Research Institute 100 Eighth Avenue SE St. Petersburg, FL 33701 727-896-8626 melanie.parker@myfwc.com

2. U.S. Army Corps of Engineers, Jacksonville District Water Flow in Florida

3. Comprehensive Everglades Restoration Plan (CERP) CERP implemented as a means of reinitiating natural freshwater flow to both coasts of south Florida Monitoring component of CERP addresses impacts of changed FW flow on the flora and fauna Eastern oyster chosen as a target species for CERP

4. Study Sites IMPACTED SITES St. Lucie Estuary Loxahatchee River Lake Worth Lagoon Biscayne Bay CONTROL SITES Tampa Bay Mosquito Lagoon Sebastian River

5. Mosquito Lagoon Pristine environment Located within Canaveral National Seashore Few anthropogenic or freshwater inputs

6. Mosquito Lagoon Stations 1 3 2

7. St. Lucie Estuary Urban environment Increasing levels of development, industry and agriculture Flood control canals and drainage ditches

8. St. Lucie Estuary Exposed to altered patterns of water quantity and quality –excess wet season flows –insufficient dry season flows –extreme salinity fluctuations –High sediment and pollutant inputs

9. St. Lucie Stations North South Central 1 1 1 2 2 2 3 3 3

10. Salinity Patterns

11. Juvenile Recruitment Monthly sampling 3 replicate spat arrays at each station Count live oysters on underside of each strung shell

12. Juvenile Recruitment

13. Abundance and Distribution Twice per year 10 replicate 1-m 2 quadrats at each station Count total live and dead oysters Measure SH of 50 live oysters

14. Abundance and Distribution

15. Perkinsus marinus (Dermo) Monthly sampling Collect and dissect 15 oysters from each site Process gill and mantle tissues with RFTM Parasite density ranked with Mackin scale

16. Perkinsus marinus (Dermo)

17. Summary Mosquito LagoonSt. Lucie estuary MeanMaxMinMeanMaxMin Salinity33.642.426.111.129.50.20 MeanS.D.%MeanS.D.% Recruitment1.352.520.281.10 Density43.053.396.2144.4 Shell Height53.026.328.48.7 Dermo0.430.71460.050.259

18. Conclusions The prevalence and intensity of dermo infection is greater at the high salinity Mosquito Lagoon site than at the more variable salinity St. Lucie site Nevertheless, oysters in Mosquito Lagoon exhibit higher recruitment rates and less variable adult populations relative to the St. Lucie estuary The indirect (negative) effects of salinity appear to exceed the direct effects of dermo on oyster health and abundance in east coast Florida waters In FLORIDA SOUTHEAST COAST ESTUARIES, it may be premature to conduct oyster reef rebuilding operations until freshwater entering those estuaries is properly managed

19. Questions?