RELATIVE ABUNDANCE OF PLANKTON OFF NAPLES, 

 FLORIDA, AND ASSOCIATED HYDROGRAPHIC DATA, 



1956-57 



Alexander Dragovich 



Fishery Research Biologist 



Bureau of Commercial Fisheries 



U.S. Fish and Wildlife Service 



Galveston, Texas 



ABSTRACT 



Some chemical, physical, and plankton characteristics of the 

 surface waters at Naples, Florida, have been investigated. Concen- 

 trations of inorganic phosphate, total phosphate, nitrate-nitrite 

 nitrogen, carbohydrate, and protein were determined over a period 

 of 17 months. Water temperatures, salinities, occurrence, and com- 

 position of phytoplankton and zooplankton were also recorded. 



INTRODUCTION 



This study adds to the hydro- 

 graphic and biological data available 

 for the Florida red tide area. It is the 

 fifth report by the U. S. Bureau of 

 Commercial Fisheries on field studies 

 of the Florida red tide. The first four 

 reports were by Grahann, Amison, and 

 Marvin (1954), Marvin (1955a), 

 Finucane and Dragovich (1959), and 

 Dragovich, Finucane, and May (1961). 

 Other studies on planktonic forms of 

 the Florida west coast have been made 

 by King (1950), Davis (1948 and 1950), 

 Davis and Williams (1950), and Gunter 

 et al. (1948). 



Knowledge of the species com- 

 position and relative abundance of 

 planktonic forms, together with as- 

 sociated physical and chemical param- 

 eters, is important in characterizing 

 a marine environment (Cleve, 1900, 

 and Russell, 1939). Previous plankton 

 analyses for the Florida red tide area 

 provide comparatively little informa- 



tion regarding coincident aquatic condi- 

 tions. In this report values for salinity, 

 temperature, inorganic phosphorus, 

 total phosphorus, nitrate-nitrite nitro- 

 gen, carbohydrate, and protein are 

 given with abundance estimates of 48 

 taxa of phytoplankton and 13 zooplank- 

 ton taxa. These data cover the coastal 

 waters off Naples, Florida, for the 

 period March 1956 to August 1957. 



MATERIALS AND METHODS 



Surface samples of water were col- 

 lected from Naples Pier at Naples, 

 Florida (lat. 26O07.9'N., long. 81048.5' 

 W. Fig. 1). The mean low water depth 

 at the pier was 5 feet with a mean 

 tidal range of 2.1 feet. Three or four 

 times a month water samples were 

 taken with 2-liter Erlenmeyer flasks 

 for chemical analysis. Imnnediately 

 after collection the samples were 

 transferred to 200 mm. pyrex culture 

 vials, capped with solid polyethylene 

 screw caps, and sealed with plastic 

 electrician's tape. They were tested 



