investigators have been unable, for various reasons to thoroughly study these events. 
The series P. crassidens mass strandings described is the third in Florida in recent 
years and occurred outside Florida Bay. An unreported stranding occurred on July 
1972 on the northeast end of Sawyer Key in Florida Bay is briefly mentioned in the 
paper. Nineteen animals were involved. 
1972 0 
Perkins, R. D., M. D. McKenzie, and P. L. Blackwelder (1972) Aragonite crystals within 
codiacean algae: distinctive morphology and sedimentary implications. Science . 
175(4022):624-26. 
[DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Morphologic studies of single 
crystals of aragonite within Codiacean algae reveal characteristic crystal forms 
produced by two distinctly different modes of calcification. Diagnostic serrated 
crystals (1 urn in length) of aragonite originating within the extracellular sheaths of 
capitular filaments are incorporated into modern lime sediments and may serve as 
effective tracers for particles of algal origin. Intercellular calcification within 
Penicillus dumetosus, previously unreported, is represented by doubly terminated 
aragonite crystals ranging in size from 48 to 160 jim. Specimens for this study were 
collected in Florida Bay. 
1972, 1987, 1989 
Thompson, M. J., and M. B. Robblee (1989) Remote monitoring of seagrass die off in Florida 
Bay, Everglades National Park, Florida. Abs., 10th Biennial Estuarine Research Conf., 
Baltimore, MD. 82. 
[ABSTRACT ONLY. NO COPY OF PAPER AVAILABLE. ABSTRACT FROM SCHMIDT (1991).] 
Extensive dying of seagrasses within climax Thalassia testudinum seagrass beds was 
first reported from Florida Bay, in the fall of 1987. Dying of seagrass beds in that area 
has continued and the phenomena appears to be spreading beyond the confines of Florida 
Bay. Aerial imagery from 1972, 1987, and 1989, and SPOT satellite imagery from 
1987 through 1989 has been used to map the extent and the rate of spread of seagrass 
destruction. Remotely monitored signatures indicative of die-off are identified and 
possibilities for future, larger scale remote monitoring are discussed. 
1973 0 
Andren, A. W. (1973) The geochemistry of mercury in three estuaries from the Gulf of 
Mexico. Ph. D. Dissertation. Florida State University, Tallahassee, FL. 140 pp. 
[DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] The distribution of Hg in three 
Gulf of Mexico estuaries of varying physical characteristics has been observed. In the 
Mississippi River approximately 100 kg Hg settles in the three main tributaries 
annually while 1.24 x 10 5 kg Hg reaches the Gulf, 78% in suspended form and 22% in 
dissolved form. In Mobile Bay 4.5 x 10 3 kg Hg settles in the estuary while 4.8 x 10 3 kg 
Hg enters the Gulf, 58% on suspended matter and 42% in dissolved form. This data 
indicates that estuaries with high sedimentation rates serve as efficient traps for 
mercury laden sediments. The Hg budget for the Everglades was not calculated but this 
area was utilized to illustrate that high levels of Hg can be encountered despite the fact 
that no Hg discharge sources are present in its vicinity. In order to study the nature of 
dissolved Hg the dissolved organic matter in the Mississippi River and the Everglades 
was fractionated into six different molecular weight ranges and Hg determined in each 
fraction. Data reveals that in the Mississippi River approximately 90% of both 
dissolved Hg and dissolved organic carbon are associated with the <500 molecular 
weight fraction. Identical measurements in the Everglades reveal that up to 40% of 
both dissolved Hg and dissolved organic matter exist in the >500 molecular weight 
fraction. Additional evidence strongly suggests that Hg is strongly associated with the 
205 
