Dawson Blood chemistry of Scophrhalmus aquosus in Long Island Sound 



435 



o 



20- 

 10 



STATION 1 



— I 1 1 1 r 



STATION 3 



J FMAMJJAS 

 MONTH 



Figure 2 



Yearly cycle of bott(.)ni temperatures at the three Long Island Sound 

 stations. Each point is the mean of all samples taken from a given 

 month and station throughout the study. 



changes. Seasonal variations encompass a variety of 

 parameters, including temperature, light, and nutrient 

 availability. It was assumed that any variations which 

 related to station rather than season were the result 

 of differences in contaminant load. The low oxygen 

 level at Station 3 during a portion of each summer may 

 be indirectly a pollutant effect because low dissolved 

 oxygen is often concomitant with organic pollution. 

 Mercury exposure produced more limited changes in 

 windowpane flounder than in other species of fish ex- 

 posed under similar conditions. Exposure to 10 t^glL 

 mercury for 60 days produced no significant changes 

 in the red cell component of windowpane flounder 

 blood. Exposure of winter flounder Pseudopleuronectes 

 americanus and striped bass Mot'one saxatiUs to the 

 same mercury concentration under similar conditions 

 reduced hematocrit, hemoglobin, and red cell count by 

 18-48% of control values (Calabrese et al. 1975; 

 Dawson 1979, 1982). The mercury-induced changes in 

 plasma chemistry observed in this study paralleled 

 those found in exposures of other species more closely 

 than did the red cells. Both winter flounder and striped 



10- 



E 

 a 



a 



z 



HI 

 O 

 >- 

 X 

 O 10- 



o 



lU 



> 



o ^ 



CO 0- 

 CO 



10 



STATION 1 



— I — I — I — I — 

 STATION 2 



— I 1 — I — I r — r 



STATION 3 



J F 



—I — 

 M 



— 1 — 

 M 



-1 1 — I — r— 



A S O N 



MONTH 



Figure 3 



Yearly cycle of dissolved o.xygen concentrations at the three stations 

 in Long Island Sound. Each point is the mean of all samples taken 

 from a given month and station throughout the study. 



bass exhibited a significant increase in sodium and a 

 decrease in calcium following mercury exposure, and 

 winter flounder also had a drop in plasma calcium con- 

 centration (Dawson 1979, 1982). The lesser effects of 

 mercury on the window])ane flounder suggest that this 

 fish is generally less susceptible than striped bass or 

 winter flounder or that the distribution of the metal 

 within the animal differs from species to species. Pen- 

 treath (1976) reported that both gill and kidney ac- 

 cumulated high concentrations of mercury during the 

 exposure of plaice Pleuronectes platessa L. to this 

 metal. Accumulation in the gill and kidney would be 

 likely to affect plasma chemistry; kidney accumulation 

 may affect renal hematopoiesis as well. 



This study produced no significant changes in win- 

 dowpane flounder blood following copper exposure. 



