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

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

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 Stations2 3 1

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 1 1 2
North
Central 3 2 3 1
South 2 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-m2 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 Lagoon St. Lucie estuary Mean Max Min Salinity 33.6
42.4
26.1
11.1
29.5
0.20
S.D. %
Recruitment
1.35
2.52
0.28
1.10
Density
43.0
53.3
96.2
144.4
Shell Height
53.0
26.3
28.4
8.7
Dermo
0.43
0.71 46
0.05
0.25 9

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?