Everglades Keys, were formerly hammock-clad. That they were formerly more 
elevated is evidenced by the rock floor of Biscayne Bay showing the same character of 
erosion as that of the present hammocks and pinelands. The fact of this one-time 
elevation is also established by the present existence of subaqueous caverns in the 
limestone, with immense stalactites which must have been formed above the water 
table 
1934 - 1986 [intermittent years] 
Powell, G. V. N., R. D. Bjork, J. C. Ogden, R. T. Paul, A. H. Powell, and W. B. Robertson 
(1989) Population trends in some Florida Bay wading birds. Wilson Bull. . 101 (3):436-57. 
Roseate spoonbills (Ajaja ajaja), reddish egrets (Egretta rufescens), and great white 
herons (Ardea herodias occidentalis) have unique subpopulations that are largely 
restricted to Florida Bay. All three species are believed to have had relatively large 
populations in Florida Bay, but the birds were virtually extirpated from the area 
between the late 1800s and the mid-1930s by human harvesting for food and feathers. 
After the birds were protected, they reestablished small populations that initially grew 
quickly. The great white heron population in Florida Bay increased from a low of about 
20 individuals after the 1935 hurricane to a population of 800-900 resident adults in 
the early 1960s. As many as 400 additional birds (juveniles and possibly seasonal 
migrants) were present in winter censuses. The population remained at about that level 
through the 1960s after recovering from a 20 - 40% decrease caused by a 1960 
hurricane. After 1968, the population was surveyed only once, in 1984, when about 
the same number of birds were censused. The reddish egret recovered more slowly 
from total extirpation around 1935 to an estimated 200-250 adults in the late 1970s. 
Casual observations in the 1980s suggest the population has remained at about that 
level. Roseate spoonbills showed an exponential recovery from just a few individuals up 
to a maximum of 2400 breeding birds by 1978-79. Subsequent censuses (1984 - 1986) 
revealed only about 800-900 nesting adults. The virtual absence of pre-1880s data 
precludes comparing present populations with those of the pristine environment. 
However, the most recently surveyed population of each of these species seems to be 
at a lower density than was historically present. The recent decline in the spoonbill 
population and low reproductive success of the great white heron population are causes 
for concern about the future of the populations. These findings point out the importance 
of continued monitoring and analysis of population trends. This study is based on 
intermittent aerial counts of great white herons between 1935 and 1968, and in 1984; 
population estimates of reddish egrets based on ground counts 1977 and 1978; and 
counts of spoonbill nests beginning in the 1930s. During the 1960s and 1970s, the 
spoonbill population of Florida Bay was also estimated from aerial reconnaissance. 
1935 - 1989 
Wanless, H. R., and M. G. Tagett (1989) Origin, growth and evolution of carbonate 
mudbanks in Florida Bay. Symp. on Florida Bay; A Subtropical Lagoon. Miami, FL. June, 
1987. Bull. Mar. ScL 44(1 ):454-89. 
Between 4,500 and 3,000 yrs ago, rising sea level inundated the area now known as 
Florida Bay. Coastal and freshwater peat and shore levee deposits, positioned by 
irregularities in the underlying limestone surface, were repeatedly embayed and 
overstepped during this transgression. Inundated and dissected coastal deposits then 
served as nuclei from which the present complex of Florida Bay islands, mudbanks, 
bank spits and bays evolved. Portions of the islands have maintained supratidal facies 
(peats and supratidal muds) throughout their growth history and are capped remnants 
of once laterally continuous coastal levees. Other portions are the result of supratidal 
progradation across younger mudbank buildups. Marine mudbanks nucleated on inundated 
coastal levees and mangrove peats. Mudbank cores are composed of layered mudstone 
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