variations in areal leaf productivity were caused by variations in leaf standing crop and 
not by variations in leaf specific productivity. Distribution, abundance, and 
productivity data were used to divide the bay into six community types. 
1979 - 1980 
Bert, T. M., J. T. Tilmant, J. W. Dodrill and G. E. Davis (1986) Aspects of the population 
dynamics and biology of the stone crab (Menippe mercenaria) in Everglades and Biscayne 
National Parks as determined by trapping. Rep. SFRC-86/04. South Florida Research 
Center, Everglades National Park, Homestead, FL. 77 pp. 
Stone crabs (Menippe mercenaria) were trapped on a lunar cycle (full moon) from June 
1979 to June 1980 to investigate the population biology and life history of the 
organism in South Florida marine waters managed by the National Park Service. 
Seventeen stations, located throughout the coastal regions of Everglades National Park 
and Biscayne National Park, were fished for an entire year. Five additional stations 
were fished the last nine months of the study. An array of morphometric and biological 
data was taken on each crab captured. Salinity, temperature, water clarity, principal 
fouling biota, and bottom type were recorded at each station during sampling. Relative 
abundance, proportion of females, and number of juveniles were highest in Everglades 
National Park marine waters from Lostmans River northward. Also, mean size of both 
sexes was generally smallest in that region. Progressing southward along the Gulf of 
Mexico and east into Florida Bay, relative abundance of both adults and juveniles 
decreased, proportion of males increased, and mean size of both sexes became larger. 
Juveniles were never found at most stations sampled in Florida Bay. Biscayne National 
Park resembled Florida Bay in number and size of adults, proportion of males, and lack 
of juveniles. Juvenile distribution and abundance was directly correlated with relative 
abundance of adults and proportion of females in the trapped population. The primary 
source of adults in Florida Bay appears to be a very slow movement of crabs from the 
Gulf of Mexico progressively farther into Florida Bay. The stone crab population in 
Biscayne National Park may be dispersing from farther north along the Atlantic coast of 
Florida. Temporal changes in relative abundance, sex ratio, and size class frequency of 
female stone crabs captured were strongly correlated to various aspects of 
reproductive activity. Changes in values of these parameters for males were related to 
changes in water temperature and female reproductive activity. Differences in relative 
abundance and mean size of both sexes also corresponded to commercial fishing season 
near the seaward limits of Everglades National Park in the Gulf of Mexico, and to the 
number, proportion, and mean size of males in commercially fished areas of Florida 
Bay. Because of the simultaneous occurrence of natural and artificial factors affecting 
the trapped population over time, it is difficult to attribute observed variations to any 
particular factor. As determined by trapping, changes in the population biology of stone 
crabs in Everglades and Biscayne National Parks occurring during the year are cyclic, 
and the population recovers to its initial state by the onset of the next year. Female 
stone crabs produce eggs throughout the summer. Younger females peak in egg 
production in late summer and older females in late spring. Young females molt and 
possibly mate more frequently than older females, but egg production of the young 
segment of the female population is reduced. By age three, all females have apparently 
reached sexual maturity. Molting occurs from fall through spring in young females and 
molt frequency declines with increasing age until, at age four, females molt annually in 
the fall. Females increase in carapace width about 10 mm with each molt and can live to 
about age seven. 
1979 - 1980 
Evink, G. L. (1981) Hydrological study in the area of Cross Key, Florida. Rep. FL-ER-16-81. 
Florida State Dept, of Transportation, Bureau of Environment, Tallahassee, FL. 
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