Laboratory experiments and field manipulations were conducted to evaluate the extent 
to which ontogenetic and certain environmental conditions interact to alter the behavior 
of juvenile Caribbean spiny lobsters following settlement. In addition we evaluated 
whether articular behavioral changes could increase a juvenile's chance of survival. We 
tested the effects of time of day, season, developmental stage and the presence of 
conspecifics on the activity state and sheltering behavior of lobsters. We also 
estimated relative predation rates by tethering lobsters under five types of shelter 
during summer and late fall. Algal phase lobsters (8-12 mm CL) were more active at 
night, and foraged more and walked less in summer than in the late fall. Post-algal 
phase lobsters (24 - 28 mm CL) were more active when in the presence of 
conspecifics. Predation rates in all seasons were highest for lobsters without cover and 
lowest while in algal cover. The proportion of algal juveniles found walking during their 
active period changed with the seasons and significantly fewer individuals foraged in 
late fall than in summer. Variation in the behavior of post-algal lobsters may reflect 
the niche shift from full-time algal dwelling to diurnal crevice sheltering yet the 
difference in predation risk between algal sheltering and crevice sheltering is not 
sufficient to explain the size at which this transition should occur. Shifting from algae 
to crevices could potentially produce a population bottleneck for lobsters in areas 
devoid of appropriate structure. This may be especially important for evaluating the 
impact of recent widespread shelter loss by sponge die-off in the Florida Bay lobster 
nursery. The lobsters used for this study were collected in Fiesta Key, Conch Key, and 
Long Key. 
1991 - 1992 
Frankovich, T. A., and J. C. Zieman (1994) Total epiphyte carbonate production on 
Thalassia testudinum across Florida Bay. Bull. Mar. Sci. . 54(3):679-95. 
Previous investigations of epiphytic carbonate production have suggested that seagrass 
epiphytes are significant producers of calcium carbonate and may be a primary source 
of lime muds in Florida Bay. This study determined total epiphyte and epiphytic 
carbonate standing stocks and calculated minimum estimates of yearly production at 
seven sites within Florida Bay and one site oceanside of the northern Florida Keys. 
These sites span a larger geographical area of increased environmental variability than 
those of previous Florida Bay epiphyte studies which were conducted in areas where 
conditions are considered favorable for epiphyte production. Total epiphyte and 
epiphytic carbonate loads along with seagrass shoot density and productivity were 
measured during four periods between August 1991 and August 1992. Epiphyte 
composition, standing stock, and production all exhibited marked variation across 
Florida Bay. Calcifying epiphytes were dominant in Florida Bay, and their distribution 
and the distribution of epiphyte production appear to reflect differences in the physical 
characteristics of salinity and the variability thereof. Minimum estimates of annual 
epiphytic carbonate production range from 1.9 g CaC0 3 nrr 2 yr 1 to 282.7 g CaC0 3 nrv 2 
yr* 1 , a range lower than previous estimates. The differences between these estimates 
and previous ones are attributed to differences in environments and, to a lesser extent, 
differences in methodology. 
1992 0 
Barber, T. R. (1992) Biogeochemistry of light hydrocarbons in South Florida wetlands. Ph. 
D. Dissertation. University of South Florida, St. Petersburg, FL. 166 pp. 
[NO COPY OF PAPER AVAILABLE.] 
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