Abstract.— This study represents 

 an attempt to distinguish between 

 normal seasonal variations and pollu- 

 tant-related changes in the blood 

 chemistry of the windowpane flounder 

 Scophthalmus aquosus. Three sta- 

 tions in Long Island Sound, USA, 

 were chosen to provide a pollutant 

 gradient. Windowpane flounder were 

 collected from the three stations 

 monthly, when possible, over a peri- 

 od of three years. Seasonal variations 

 were noted in hematocrit, plasma os- 

 molality, sodium, potassium, and cal- 

 cium. Station-related differences were 

 demonstrated in osmolality, hemato- 

 crit, and hemoglobin. The same spe- 

 cies was subjected to 60-day labora- 

 tory exposures to mercury, cadmium, 

 or copper. Neither copper nor cadmi- 

 um produced a significant difference 

 in any variable measured. Following 

 exposure to mercury, there were sig- 

 nificant differences between controls 

 and exposed animals in plasma sodi- 

 um and calcium. 



Blood Chemistry of 

 the Windowpane Flounder 

 Scophthalmus aquosus '\n Long Island 

 Sound: Geographical, Seasonal, 

 and Experimental Variations 



Margaret A. Dawson 



Milford Laboratory, Northeast Fisheries Science Center 



National Marine Fisheries Service, NOAA, Milford. Connecticut 06460 



Manuscript accepted 26 March 1990. 

 Fishery Bulletin, U.S. 88:429-4.37. 



The geographical situation of Long 

 Island Sound presents unique ques- 

 tions on the distribution of anthropo- 

 genic pollutants and the effects of 

 such pollutants on the resident ani- 

 mal population. The western end of 

 the Sound is heavily populated and 

 industrialized. Much of the bottom in 

 the western portions of the Sound 

 consists of fine-grained sediments, 

 with a potential for adsorbing and re- 

 taining contaminants (Hunt 1979, 

 Reid et al. 1979). Tidal flushing is 

 limited in the far western end of the 

 Sound; it has been reported that ex- 

 change with the East River adds 15 

 m'Vsecond of effluent to western Long 

 Island Sound (Bowman 1976). 



In contrast, the more eastern por- 

 tions of the Sound are open to consid- 

 erable tidal flushing and are bordered 

 by less populated and less industrial- 

 ized areas. There is a decrease in fine- 

 grained sediments from west to east 

 with a concomitant decrease in the 

 capacity of the sediment to retain 

 contaminants (Hunt 1979, Reid et al. 

 1979). The physical and geographical 

 differences are reflected in an in- 

 crease from east to west in sediment 

 levels of heavy metals (Greig et al. 

 1977, Hunt 1979, NOAA 1988), 

 PCBs (Chytalo 1979, NOAA 1988), 

 and PAHs (NOAA 1988). 



The present study is an attempt to 

 assess the effects on a local species 

 of the contaminant levels found in 

 Long Island Sound. Stations were 

 selected on the basis of providing a 



pollutant gradient and of being 

 located within an area that could be 

 sampled on a day-trip basis, thereby 

 expediting monthly sampling (Fig. 1). 

 Station 1 was off Roanoke Point, 

 New York (lat. 40°58'50"N, long. 

 72°45'00"W), near the eastern end of 

 the central basin. Reid et al. (1979) 

 reported that this station had less 

 than 5% fine-grained sediments. 

 Greig et al. (1977) reported a sedi- 

 ment cadmium concentration of 1.1 

 mg/kg dry weight, a copper concen- 

 tration of 4.0 mg/kg, and a lead con- 

 centration of <6.0 mg/kg. Station 2 

 was off Milford, Connecticut (lat. 

 40°09'01"N, long. 73°00'00"W), near 

 the western end of the central basin. 

 Reid et al. (1979) reported that this 

 station had a fine-grained sediment 

 level between 5 and 50%. Greig et al. 

 (1977) reported sediment cadmium 

 and mercury levels below detectable 

 limits, a copper concentration of 43.3 

 mg/kg, and a lead concentration of 

 19.0 mg/kg. Station 3, Hempstead 

 Harbor, New York (lat. 40°53'50"N, 

 long. 73°49'90"W) is in the western 

 end of Long Island Sound. Reid 

 et al. (1979) reported a fine-grained 

 sediment content of >50%. Greig 

 et al. (1977) reported a cadmium con- 

 centration of 1.4 mg/kg, a copper 

 concentration of 175.0 mg/kg, a mer- 

 cury concentration of 0.7 mg/kg, and 

 a lead concentration of 110.0 mg/kg 

 in the sediment. NOAA (1988) re- 

 ported a total PCB concentration of 

 255.5 /.(g/kg and a total PAH concen- 



429 



