congeners (NAS 1979; Johnson and Finley 1980; EPA 1980). 



Since PCBs are highly lipophilic, greatest concentrations were expected, 

 and occurred, in fatty tissues. For example, lipid content in muscle of brown 

 trout ( Salmo trutta ) was the best correlate of PCB concentration in muscle 

 (Spigarelli et al . 1983). Differences in PCB content of tissue lipids were 

 negatively correlated with phospholipid fractions in total lipid extracts; the 

 higher the phospholipid fraction, the lower the PCB content in organ lipids. 

 This has been verified experimentally in codfish and other species of marine 

 teleosts (Boon et al . 1984), and probably should be explored in greater detail 

 for other trophic levels. Other factors known to modify PCB accumulations in 

 aquatic biota include: temperature magnitude and variation for trout 

 (Spigarelli et al. 1983); time of incubation and age of larvae for mosquitos 

 (Gooch and Hamdy 1983); presence of mineral oils on PCB-contaminated 

 substrates for chironomid larvae (Meier and Rediske 1984); and diet for 

 teleosts (Pizza and O'Connor 1983; Spigarelli et al . 1983; 'Conner and Pizza 

 1984). Of these, diet contributes most of the total PCB body burdens of upper 

 level carnivores. For example, diet accounted for 90% of the total PCB body 

 burden in brown trout (Spigerelli et al . 1983), and 51 to 83% in striped bass 

 (Pizza and 'Conner 1983). PCB body burdens in striped bass were lower in 

 winter during nonfeeding periods, and lower when fish migrated to a new area 

 where dietary PCB levels were lower (O'Connor and Pizza 1984). Prey species 

 of carnivores accumulate PCBs through contaminated sediments. PCB transfer 

 through aquatic ecosystems has been reported in the Great Lakes using a 

 sediment-lake trout model (Jensen 1984), and in New York Harbor from 

 contaminated sediments to clams, shrimp, and especially nereid worms 

 (Rubenstein et al . 1983). 



Depuration of accumulated PCBs is slow, and slower yet at reduced 

 temperatures (Zhang et al . 1983). Larvae of codfish exposed to PCBs as eggs 

 showed no elimination after 12 days. Uptake of PCBs by yolk sac larvae was 

 higher than in eggs; 60% of the PCBs remained after 15 days (Solbakken et al . 

 1984b). Larvae of chironomids ( Glyptotendipes barbipes ), held for 24 days in 

 substrates containing 1,000 mg Aroclor 1242/kg, contained 18.0 mg Aroclor 

 1242/kg fresh weight; 7 days later, larvae still retained 97.8% of the total 

 (Meier and Rediske 1984). Tissue samples of a Bermuda brain coral ( Diploria 

 strigosa ) taken 9 months after initial exposure for 24 hours to radiolabeled 

 2,4,5,2' ,4' ,5'-hexachlorobiphenyl contained 84% of the original radioactivity 

 (Solbakken et al . 1984a). Rainbow trout fed 1,150 mg Aroclor 1254/kg body 

 weight contained high residues in various tissues 38 days posttreatment: 70 

 mg/kg in muscle on a fresh weight basis, 33 in liver, and 6 in gill filament 

 (Kiessling et al . 1983). Factors affecting elimination of Aroclor 1254 by 

 marine crustacean copepods ( Acartia tonsa ) include diet and reproductive state 

 (McManus et al . 1983). Copepods fed during depuration eliminated PCBs more 

 rapidly than unfed copepods. PCBs in copepod eggs were up to 4X the 

 concentration in females producing them. Females eliminated PCBs twice as 

 rapidly as males, indicating that egg production is an important route for PCB 

 elimination. Fecal pellets were the most significant elimination route, but 

 levels in fecal pellets from both sexes decreased over time suggesting a 

 multiphasic elimination pattern. In fish, egg maturation and spawning result 



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