regressive tendencies are seen and the shoreline has prograded. The view of Davis of 
generally regressive sequence and general coastal progradation is not supported. The 
accretionary beach ridges of the three capes of Cape Sable are tentatively dated as 
having begun to form as early as 2000 yrs BP at Northwest Cape and 1200 yrs BP at 
East Cape. Shorelines older than the accretion beach ridges also exist in the Cape Sable 
area. These have not been dated but their prominent surface expression would seem to 
allow only slight rise of the sea over the land in the time since they were abandoned. 
The dates on the Beach ridges suggest this was over 2000 yrs. Major trends in 
mineralogical constituents in carbonate mud cores are not evident. Differences that are 
seen are usually coincident with other changes that indicate environmental change. 
There are indications that the peat layers affect carbonate sediments to some extent. 
Shells near the contacts are soft and decomposed. High magnesia calcite tends to 
decrease in amount toward the contacts with the peat. Important amounts of non- 
calcareous clay sized sediment occur in the tidal area but have been little noted in 
earlier reports. These are most abundantly accumulated in the mangrove swamps. A 
stiff clayey sand underlies much of the area north of the Shark River and this may be of 
Pleistocene age. Clays of the Holocene may be partly derived from this and partly from 
materials transported in from the Gulf of Mexico. The clays are highly organic and are 
possibly residuals after loss of carbonate originally carried into the swamps. In the 
freshwater areas clays often occur next to the bedrock in a thin dark organic zone. 
1964 - 1965 
Beardsley, G. L. (1967) Distribution in the water column of migrating juvenile pink shrimp, 
Penaeus duorarum, Burkenroad in Buttonwood Canal, Everglades National Park, Florida. Ph. 
D. Dissertation., University of Miami, Coral Gables, FL. 91 pp. 
[NO COPY OF PAPER AVAILABLE. ABSTRACT FROM SCHMIDT (1991).] Distributional 
studies on migrating pink shrimp showed that they occurred in the Buttonwood Canal at 
various times. Shrimp were found on the surface of the canal under all conditions based 
on an analysis of the relation between environmental factors and distributional 
patterns. However, a greater percentage were observed on the surface during full 
moon periods. Evidence from Coot Bay also indicated that juveniles respond positively 
to moonlight during their emigration. No differences in vertical distribution were 
detected in relation to temperature, salinity, current velocity, changes in water depth, 
or sex. Changes in lateral distribution, however, occurred in the canal. When moving 
out with the tide, juveniles commonly cling to drifting vegetation, and their distribution 
is probably affected by prevailing winds when large amounts of vegetation are present 
in the water. At other times current patterns showed no features that might contribute 
to changes in lateral distribution. Mean carapace length and sex ratios were 
determined. 
1964 - 1965 
Beardsley, G. L. (1970) Distribution of migrating juvenile pink shrimp, Penaeus duorarum, 
Burkenroad, in Buttonwood Canal, Everglades National Park, Florida. Trans. Am. Fish. Soc.. 
99(2):401 -8. 
[NO COPY OF PAPER AVAILABLE. ABSTRACT FROM SCHMIDT (1991).] The vertical and 
lateral distribution of migrating pink shrimp, Penaeus duorarum, was studied in 
Buttonwood Canal by thrice monthly sampling with conical nets suspended from a 
bridge. Vertical and horizontal movements of juveniles correlated with moonlight and 
tide. During ebb tide, juveniles exhibited a positive response to moonlight, by moving to 
the surface. During flood tides they stayed on the bottom or at the sides of the canal. 
175 
