positively rheotactic. However, with a decrease in salinity the sign of the response 
was reversed, resulting in active downstream swimming. This often gave way to 
passive drifting. Under conditions of low light intensity postlarvae were active in the 
water column, and being unable to withstand even slow currents were easily displaced. 
With a decrease in salinity they sank to the substrate or remained low in the water 
column where they were better able to maintain position. Responses of postlarvae at a 
discontinuity barrier between bodies of water differing in salinity indicated their 
ability to perceive differences as small as 1 %o. There was an 'aversion* to 
penetrating such a barrier into water of lower salinity. Smaller postlarvae were more 
'averse' to the barrier than others approximately a week older. If similar responses 
are elicited in nature during the flood tides, juveniles would orientate and swim against 
the current in an offshore direction, while postlarvae, by being active in the water 
column, would be displaced shoreward. Following the decrease in salinity which 
accompanies the ebb tide the juveniles would swim, or be passively displaced, with the 
current, again in an offshore direction, and the postlarvae would sink low in the water 
column or settle on the substrate from where they are better able to resist 
displacement. 
1969 0 
Manker, J. P., and G. M. Griffin (1969) Distribution of silicate minerals in Florida Bay. 
Geology of the American Mediterranean. Gulf Coast Assoc. Geol. Soc. Trans .. 19:505. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] The dominantly 
carbonate sediments within Florida Bay contain small percentages of insoluble silicate 
minerals, ranging in our samples from 1.25 to 14.91% by weight. Quartz chlorite, and 
montmorillonite compose most of the silicate fraction, with very minor amounts of 
illite and kaolinite. Clay mineral distribution can be described by concentration 
gradients based on two end member assemblages: A chlorite assemblage dominates in 
the eastern part of the Bay, but declines westward. In a reciprocal manner, a 
montmorillonitic assemblage dominates the western bay and declines eastward. The two 
clay mineral assemblages reflect different sources-chlorite from the Atlantic 
province, and montmorillonite from the Gulf of Mexico province. Shallow and subaerial 
carbonate mud banks and intervening basins inhibit mixing of waters bearing the two 
clay assemblages; this has caused the relatively rapid transition from one clay suite to 
another in the 30-40 mile span of Florida Bay. The clay mineral fractions of similar 
ancient carbonate reef trends would be expected to show analogous concentration 
gradients in the back-reef area. 
1969 0 
Scholl, D. W., F. C. Craighead and M. Stuiver (1969) Florida submergence curve revised: 
Its relation to coastal sedimentation rates. Science . 163:562-4. 
[DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] New data substantiate as well as 
modify the south Florida submergence curve, which indicates that eustatic sea level has 
risen continuously, although at a generally decreasing rate, during the last 6500 to 
7000 sidereal yrs (5500 standard radiocarbon yrs) to reach its present position. 
Accumulation rates of coastal deposits are similar to the rate of sea-level rise, thus 
supporting the generalization that submergence rates largely determine as well as limit 
rates of coastal sedimentation in lagoonal and estuarine areas. 
1969, 1971 
Russel, R. J. (1971) Beaches and ground water of Cape Sable, Florida, during extreme 
drought. Tech. Rep. No 103. Coastal Studies Institute, Louisiana State University, Baton 
Rouge, LA. 18 pp. 
194 
