The biomass of algae was very small compared to that of the seagrasses; how- 

 ever, the algae served as a resource for animals and reduced light over the 

 seagrass beds. 



24. DOWN, C, and WITHROW, R. , "Vegetation and Other Parameters in the Brevard 

 County Bar-Built Estuaries," Report No. NASA-CR-158242, Report-06-73, 

 Brevard County Health Department, Titusville, Fla., 1973. 



Low-altitude aerial photography, using specific interpretive techniques, 

 can effectively delineate seagrass beds, oysterbeds, and other underwater 

 features. Imagery was tested using several data analysis methods, ground 

 truth, and biological testing. Approximately 45,000 acres of seagrass beds, 

 2,500 acres of oysterbeds, and 4,200 acres of dredged canals were mapped. 

 These data represent selected sites only. Areas chosen have the highest 

 quality water in Brevard County and are among the most highly recognized 

 biologically productive waters in Florida. 



25. DRYSDALE, F.R. , and BARBOUR, M.G., "Response of the Marine Angiosperm 

 Phyllospadix torreyi to Certain Environmental Variables: A Preliminary 

 Study," Aquatic Botany, Vol. 1, 1975, pp. 97-106. 



Leaf growth of Phyllospadix torveyi was noted both in the field and in 

 laboratory culture. Field winter growth rate did not appear to depend on 

 aspect or slope of substrate. In that part of the intertidal zone which 

 P. tovveyi dominates, average dry weight of leaf material was about 300 grams 

 per square meter. It was hypothesized that the spring growth rate is greater 

 than the measured winter rate, and that increasing daily incident light energy 

 triggers the change. In the laboratory cultures, optimum growth occurred in 

 full strength seawater (29,000 parts per million), under 100-lumen-per-square- 

 foot light intensity (12-hour day), and at a water temperature of 12° to 14° 

 Celsius. Growth declined in lower salinities, under lower light intensities, 

 and at higher temperatures. However, the magnitude of decline indicated that 

 tolerance ranges of P. toweyi for salinity, light, and temperature are 

 relatively broad. 



26. EARLE, S.A. , "Benthic Plants in the Eastern Gulf of Mexico," Pvoceedings 

 of Marine Environmental Implications of Offshore Drilling in the Eastern 

 Gulf of Mexico, R.E. Smith, ed. , State University System of Florida, 

 Institute of Oceanography, St. Petersburg, Fla., 1974, pp. 153-156. 



Benthic plants in the Gulf of Mexico have considerable influence on shore 

 primary productivity, due to the broad, shallow Continental Shelf. Seagrasses 

 and algae are significant biologically by providing a substrate for inverte- 

 brates, and geologically by precipitating calcium carbonate from seawater. 

 There is little information available on the ecology, distribution, and 

 general biology of benthic plants in the gulf. 



27. EDWARDS, P., "Illustrated Guide to the Seaweeds and Seagrasses in the 

 Vicinity of Port Aransas, Texas," Contributions in Marine Science, 

 University of Texas Marine Science Institute, Austin, Vol. 15 (supp.), 

 Sept. 1970. 



This report provides a key to the identification of species of algae and 

 seagrasses, including Thalassia, Ruppia, Diplanthera, and Halophila, along the 

 Texas coast. 



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