II-C-7 



Ragotzkie, R.A., and L.R. Pomeroy. 1957. Life history of a dinoflagellate 

 bloom. Limnology and Oceanography 2:62-69. 



In late February and early March 1955, a small, dense concentration 

 of a dinoflagellate of the genus Gymnodinium was observed in the 

 extreme upper end of the Duplin River at Sapelo Island, Georgia. 

 This river is estuarine in character and receives practically no 

 freshwater runoff from land. 



The authors describe the bloom in terms of its distribution, growth 

 rate, production, and rate of diffusion. Production measurements 

 on a second bloom of the same organism are also cited. In the center 

 of the first bloom, cell concentrations ranged from 1 to 18 million 

 cells per liter. Net production ranged from 2.18 to 13.7 mg C/liter/day. 

 Coefficients of horizontal eddy diffusion, as calculated from the oberved 

 dinoflagellate distributions, were low, ranging from near zero to 

 350 g/cm/sec. (A. A. and introduction) 



Keywords: dinoflagellate, estuary, Georgia 



II-C-8 



Ragotzkie, R.A. 1959. Plankton productivity in estuarine waters of Georgia. 



Publications of the Institute of Marine Science, University of Texas 



6:146-158. 



Primary production of the plankton community in the estuarine waters 

 near Sapelo Island, Georgia, was estimated by oxygen evolution in light 

 and dark bottles at several locations. Data on temperature, light, 

 and chlorophyll a^ were obtained for most of the experiments. The 

 average gross production by plankton was +0.68 gm C/m^/day, and net 

 planktonic community production averaged -0.038 gm C/m^/day. The plankton 

 community tended to be heterotrophic in the summer and autotrophic in 

 the winter. The primary factor limiting production was light. Analysis 

 of compensation depths and extinction coefficients shows that, for the 

 mean depth of these waters and under the observed conditions of 

 light and vertical mixing, net production by the plankton community 

 must be near zero regardless of the standing crop. The salt marsh is 

 postulated as an outside source of organic matter of the system. (A. A.) 



Keywords: primary productivity, plankton, estuary, Georgia 



70 



