in previous studies (Dragovich and May, 1962). 



Temperature, salinity, clilorophyll "a," oxygen, 

 total j)hosphorus, inorganic phosphate-phosphorus, 

 copper, and iron were measured. 



Copper was included in our past studies and in 

 the present one because its high toxicity to 

 laboratory cultures of G. breve suggested that it 



might be a limiting factor in the physiology of 

 this species in luxtural waters. It was determined 

 only in the Myakka, Peace, and Caloosahatchee 

 Rivers because earlier studies in Tampa Bay 

 tributaries revealed that the concentrations there 

 were nontoxic to G. breve (Dragovich and May, 

 1962). 



MEXICO 



C«PIIV« 

 ISltNO 



81" 0' 



464 



■i(;i:nE 1. — We.st coast of Florida showiiin rivors, sampling locations, and weather and gage stations. 



Vi.a. FISH AND WILDLIFIO SEKVICK 



