UPTAKE AND DISTRIBUTION OF 2,4,5,2',4',5'-HEXACHLOROBIPHENYL IN FRY OF LAKE TROUT AND CHINOOK SALMON AND ITS EFFECTS ON VIABILITY

Lake trout (Salvelinus namaycush) and Chinook salmon (Oncorhynchus tshawytscha) sac fry were exposed to water containing low ppb (μg/liter) concentrations of 14C-labeled 2,4,5,2′,4′,5′-hexachlorobiphenyl (HCB). The HCB was added to the water in a static system three times per day for 15 days, each addition being a calculated water concentration of 5 ppb. Although the HCB did not accumulate in the water, it did accumulate in the fry of both species, reaching a concentration of 7.6 ppm in lake trout and 3.6 ppm in Chinook salmon, 1 day after the last addition. Subsequently, all the HCB-treated fry died: All the lake trout fry died by 64 days, and all the Chinook fry by 16 days, after the last addition of HCB. For each species it was found that the amount of HCB present in the fry at the time of death was constant, no matter when the animals died. In a separate experiment, sac fry of both species were exposed to 500 ppb [14C]HCB in the water for 4 hr, and the amount of HCB in the fry was followed for 3 months. The data indicate that some of the HCB was lost from the fry after 3 months. Analyses of yolk and other fry tissues during the 3-month period indicated that the localization of the HCB in the animals shifted with time and that large amounts were present in the digestive organs at 3 months after exposure. © 1979.