Baldwin, John D.

This project tested the effects of water conditions on developmental rates of larvae of the estuarine sea anemone Nematostella vectensis . Egg masses were collected immediately following fertilization and placed in solutions with different salinities and maintained in a temperature-controlled water bath. Every twelve hours, embryonic development was checked for progression through different morphological stages of development. Comparison of regression analyses of larval development at each temperature increment indicated that both temperature and salinity affected the rate of development; development was slower in lower conditions and faster at higher salinities and temperatures, with extreme conditions inducing deleterious effects. The suggested ideal conditions for these larvae are a salinity range of 12.5--20% and a temperature range of 22--24C. These parameters provide a foundation from which a standardized testing method may be established, using N. vectensis larval development.

This study reports on a community of bottlenose dolphins found >27 km from Grand Bahama Island. Observations were conducted from May--September, 1993--2002. The half weight index determined coefficients of association (COA) between dolphins for each year and from pooled data over the 10-year period. Long-term site fidelity of up to 17 years occurred. Resident and non-resident dolphins occurred in the area. Some dolphins traveled 333 km between communities. Average group size was 3--5, and significantly larger with calves. Traveling groups were significantly smaller than feeding or socializing. Mother-calf associations were the strongest. Male-male COAs were low (x = .34), however, some individuals formed strong associations. Female-female COAs were low (x = .35), and affected by female reproductive status. Mixed-gender COAs were significantly lower (x = .31) than same sex associations. Pooled data revealed lower COA values, however, the same trends were evident. The long-term associations revealed from yearly COAs were not seen when data were pooled.

The toxicity of endosulfan, a restricted use pesticida, and copper sulfate, an anti-algal agent, ranks among the highest in all insecticidas. Both chemicals, used in agricultura fields of southern Florida, are known to be highly toxic to aquatic invertebrates. Since Palaemonetes pugio, an extensively studied brackish water shrimp species, has proven to be excellent for toxicological analysis, a closely related freshwater shrimp species, Palaemonetes paludosus, was used as the test species in this study to determine the toxicity of endosulfan and copper sulfate in freshwater. A series of static renewal 96 h bioassays (renewed every 24 h) performed on juvenile P. paludosus resulted in the 96 h lethal concentration (LC50) estimates of 0.24 mug/L (0.24 ppb) for endosulfan and 0.79 mg/L (0.79 ppm) for copper sulfate. The results of this study, when compared to other studies, indicate that P. paludosus is more sensitive to endosulfan and copper sulfate than other similar aquatic invertebrate species and is therefore an excellent toxicological indicator.

Acropora cervicornis is an important Caribbean shallow water reef building coral species which is currently federally protected, and a candidate for the U.S. endangered species list. A. cervicornis is an excellent candidate for fragment salvage or reef transplantation because it exhibits rapid growth rates, can be successfully fragmented, and is tolerant to a wide range of light intensities. The success of restoration efforts for A. cervicornis is dependent upon the complete understanding of its growth parameters. This study documents the culture conditions for growing A. cervicornis in a closed system, and the effects of fragment size and light intensity on growth and survivorship. A. cervicornis was successfully fragmented and grown under aquaculture conditions. Fragment size significantly effected percent weight gain growth rates, but did not significantly effect absolute weight gain growth rates. Light intensity significantly effected absolute weight gain growth rates, but did not significantly effect percent weight gain growth rates.

Mitochondrial DNA and nuclear microsatellite analyses were performed on Malaclemys terrapin data. These analyses investigated the genetic variation among subspecies of M. terrapin throughout their range and sought to determine if hurricane mitigated dispersal occurs among populations of a single subspecies, M.t. rhizophorarum. The 700bp mtDNA fragment, ND4-Leu, provided only 1bp transition, and the 421bp D-loop, DES1-DES2, revealed no genetic variation between the seven subspecies. Four polymorphic loci were examined for the microsatellite analyses. These analyses revealed an average pairwise RST of 0.018. This indicates very close genetic identities between the two temporally sampled populations before and after Hurricane Georges. The average FST and GST values were 0.101 and 0.216 respectively. It can be noted that the RST values were able to correct for microsatellite mutation mechanisms. The results indicate that significant storm dispersal did not occur.