Aswani Volety

A stressor response model in the form of a habitat suitability index was created for blue crab to quantify impacts of alternative management actions and to assist managers in policy decisions. The model simulates system response by examining impact of freshwater input into southwest Florida estuaries and is being used to help bring together research and monitoring components within southwest

The hydrology and watershed of the Caloosahatchee River and Estuary located on the southwest coast of Florida has been altered since the 1880’s. The river has also been straightened, deepened and three water control structures have been added. The last, Structure S-79, was completed in 1966 to act, in part, as a salinity barrier. These alterations have resulted in huge fluctuations in freshwater input into the estuary resulting in extreme salinities with near freshwater conditions in the wet summer months and saline to hypersaline conditions in the winter months. The transition between the two states can be rapid, sometimes requiring less than a week. As part of the Comprehensive Everglades Restoration Plan (CERP), several storage facilities are being planned to retain freshwater during high flow periods, with subsequent release to the estuary during drier times thereby reducing high discharges during the wet season and provide a base flow during the dry season. The premise of CERP ...

The hydrozoan Eutima sp. is an inquiline symbiont known to infest the gills of the eastern oyster Crassostrea virginica (Gmelin, 1791) in Florida waters. Although it is unclear whether Eutima sp. polyps impact oyster fitness, access to bivalve hosts plays a role in sustaining Eutima sp. populations within estuaries. In addition, reduced salinities associated with high levels of freshwater inflow (e.g., monsoons) have been implicated in influencing the distribution and abundance of hydrozoan medusae and polyps. We investigated the influence of variable freshwater inflow and salinity on medusa and polyp stages of Eutima sp. in Estero Bay, an estuary subjected to seasonal extremes in precipitation. Medusae were collected using plankton nets, and polyps were identified from oysters sampled along two transects within the bay. Polyp prevalence (%) at one site was zero when freshwater inflow 7 wks prior to sampling exceeded 0.5 m3 s−1, was reduced upstream along one of the transects at a s...

... SURVEY OF WATER QUALITY, OYSTER REPRODUCTION AND OYSTER HEALTH STATUS IN THE ST. LUCIE ESTUARY. C. WILSON 1 , * , L. SCOTTO 2 , J. SCARPA 3 , A. VOLETY 4 , S. LARAMORE 3 , and D. HAUNERT 5. ... Lucie Estuary (SLE), located near Stuart, Florida. ...

Perna viridis is a recently introduced species to US coastal waters and have vigorously spread throughout the southeastern seaboard since their invasion. Little information regarding their response to local environmental factors has been reported including responses to the local HAB species, Karenia brevis. This study monitored the tissue toxin concentration of brevetoxins in P. viridis from existing populations throughout two consecutive natural K. brevis blooms. The results showed P. viridis to rapidly accumulate PbTx upon exposure to the bloom, far exceeding the peak tissue concentrations of oysters, Crassostrea virginica, sampled during the same period, 57,653 ± 15,937 and 33,462 ± 10,391 ng g(-1) PbTx-3 equivalent, respectively. Further, P. viridis retained high PbTx concentrations in their tissues post bloom remaining above the regulatory limit for human consumption for 4-5 months, significantly longer than the depuration time of 2-8 weeks for native oyster and clam species. I...

The bivalve mollusc, Crassostrea virginica, is frequently exposed to blooms of Karenia brevis along the west coast of Florida during periods of spawning and early larval development. A continuous 4-day exposure of gametes and 2-4 cell stage embryos of C. virginica to whole-cell and culture filtrate of K. brevis at 500 and 5000 cells mL(-1), was followed by a 4-day 'recovery' period. Larval growth, percent of normal, abnormal and dead larvae, and the presence of food in the larval gut were measured throughout the exposure period. Results suggest that negative effects mainly occur during embryogenesis and early development. Damage to feeding apparatus/gut may occur during embryonic development or exposure to toxins may act as a feeding deterrent on non-toxic algae. Following 2-h in vitro exposure of gametes, differences in oocyte and sperm cell parameters were investigated using flow cytometry. The reduced sperm viability in the whole-cell 5000 cells mL(-1) treatment suggests ...

... 364, Fort Myers, FL 33901. & Bruce Boler US Environmental Protection Agency, 3745 Broadway Street, Suite ... Thanks are also due to Mr. James Winstead of the US Environmental Protection Agency, Gulf Breeze, Florida, for his help on histology of oyster tissue. 5 Page 7. ...