430 



Fishery Bulletin 88(3). 1990 



Connecticut 



New Haven. 

 MKforc 



-4r30 



-4roo' 



Figure 1 



Long Island Sound stations sampled for Scophthalniu,'^ nqmnnts: Station 1, off Shoreham, NY, 5.5 m; Station 2, off 

 Milford, CT. 15.2 m; Station 3, Hempstead Harbor, NY. 10. T m. 



tration of 5366 i^glkg in the sediments of Hempstead 

 Harbor. 



The windowpane flounder Scophthalrmis aquosus was 

 chosen as a test animal because it is one of the few 

 species available in the Long Island Sound area 

 throughout the year. The possibility of some movement 

 between stations is a consideration in this type of study. 

 However, Moore (1947) reported on the basis of tag- 

 ging studies that, although individuals have been shown 

 to move over large distances, no seasonal migration of 

 windowpane flounder is indicated and that this species 

 is relatively stationary. 



This study utilized blood chemistry as an indication 

 of stress in the fish. Several investigators have sug- 

 gested that the study of blood may ultimately be as 

 useful in assessing the health of fish as it is in diagnos- 

 ing human health (Blaxhall and Daisley 1973, Hickey 

 1976). Fish blood chemistry has not received the same 

 critical study as has human (Wedemeyer and Yasutake 

 1977). A given species of fish in its normal habitat is 

 likely to be subjected to a wide range of natural condi- 

 tions, any of which may be reflected in its blood chem- 

 istry. Johansson-Sjobeck et al. (1975) noted that 

 hematocrit increased and hemoglobin decreased in eels 

 subjected to starvation, both returning to control levels 

 within 164 days. DeWilde and Houston (1967) reported 

 an increase in hematocrit and hemoglobin with an in- 

 crease in acclimation temperature in rainbow trout; the 

 degree of response depended on season. Effects of 

 heavy-metal exposure on fish blood have been demon- 

 strated (Christensen et al. 1972; Calabrese et al. 1975; 

 Dawson 1979, 1982). Within the same species, fresh- 

 water-adapted fish often exhibit blood chemistry which 

 is different from that of fish adapted to seawater (Cour- 



tois 1976). Snieszko (1960) emphasized the need to con- 

 sider two sets of standards in using hemotological 

 methods in hatcheries: one general standard for the 

 species, and a second standard that determines a nor- 

 mal value for the parameter at a particular hatchery. 



Although the objective of the present study was to 

 obtain information on pollutant-related stress, it was 

 necessary to consider seasonal changes as well in order 

 to distinguish between the effects of pollutants and 

 those that represent a normal response to changing 

 natural conditions. Although seasonal changes in fish 

 blood have received little attention in the literature, 

 such changes have been documented in the winter 

 flounder (Bridges et al. 1976), the striped bass (Loch- 

 miller et al. 1989) and the rainbow trout (DeWilde and 

 Houston 1967). In addition, the values for hematologi- 

 cal measurements vary from species to species, but few 

 species have received sufficient study to allow a real- 

 istic estimate of their normal ranges under a reasonable 

 variety of conditions. 



The field study described here was supplemented by 

 a series of three laboratory exposures of the same 

 species to heavy metals. Although laboratory exposures 

 are subject to criticism on the grounds that they do not 

 correspond closely to natural conditions, they do make 

 it possible to attribute changes to a particular pollu- 

 tant, which is not often possible in the field. 



Materials and methods 



Field study 



Windowpane flounder for the field study were collected 

 by otter trawl using 30-minute tows at the three desig- 



