were evident; skinless fillets of Great Lakes salmon contained significantly 

 lower PCB residues than skin-on fillets, with Aroclor 1254 concentrations 3.5 

 to 4X lower in the skinless fillets (Table 2). Also, a strong correlation was 

 observed between the concentration of PCBs and DDE in Great Lakes salmon 

 collected in 1980 (Rohrer et al . 1982), probably due to the chemicals' similar 

 polarity and molecular size. The chemical interactions of PCBs with other 

 chlorinated hydrocarbon contaminants, and their biological properties, are 

 areas requiring additional research effort. 



Although diet is a major route of PCB uptake in many species of fish, 

 there are notable exceptions--even among closely related species. In lake 

 trout ( Salvelinus namaycush ), for example, most (more than 99%) accumulated 

 PCBs are from the diet and less than 1% from the medium. However, water is 

 the major PCB uptake route in coho salmon (Rohrer et al . 1982). In the 

 windowpane ( Scopthalmus aquosus ) , a marine flounder from Long Island Sound, 

 New York, stomach contents contained up to 0.45 ppm of PCBs fresh weight, 

 suggesting a potentially large amount of dietary PCBs available to this 

 species (Greig et al. 1983). 



Elevated levels of PCBs (mostly Aroclor 1254) found in gonads of striped 

 bass ( Morone saxatilis ), up to 1.4 ppm fresh weight and 2.3 on a lipid basis, 

 may be associated with poor reproductive success of this species in Nova 

 Scotia (Ray et al. 1984). This is similar to levels of 2.8 ppm PCBs in lipids 

 of eggs of rainbow trout ( Salmo gairdneri ) that experienced heavy fry 

 mortality (Rohrer et al. 1982), and to levels of 0.12 ppm PCBs on a fresh 

 weight basis in gonads of flounder ( Platichthys flesus ) with inhibited 

 reproduction (Ray et al. 1984). However, eggs of Atlantic salmon ( Salmo 

 salar ) with 6.0 ppm PCBs in lipids hatched normally (Ray et al. 1984). It is 

 clear that considerable interspecies differences exist in the responses of 

 teleosts to PCB loadings. 



Equilibrium levels of stable lipophilic contaminants in fish are directly 

 proportional to the ambient water concentration of the chemical. Atmospheric 

 deposition and high sediment contamination have also been implicated as major 

 sources of PCB contamination (Rohrer et al. 1982). Lowest PCB levels in Great 

 Lakes salmon were at stations with high flushing and high sedimentation rates 

 (Rohrer et al . 1982). PCBs were detectable at low concentrations in brook 

 trout ( Sal vel inus fontinal is ) from remote New England lakes, tending to 

 confirm that PCBs, and other recorded contaminants, reached the lakes by 

 atmospheric deposition (Haines 1983). 



REPTILES 



Water snakes ( Nerodia spp.) collected in Louisana reflected PCB levels 

 similar to those of PCB residues in their prey species, primarily fresh- and 

 brackish-water teleosts. PCBs in water snakes were detected in 95% of all fat 

 samples and 52% of liver and muscle tissues; Aroclor 1260 accounted for most 

 of the PCBs (Sabourin et al . 1984). Snapping turtles ( Chelydra serpentia ) are 



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