EFFECT OF DIETARY MIREX AND PCBS ON HEPATOSOMATIC INDEX, LIVER LIPID, CARCASS LIPID AND PCB AND MIREX BIOACCUMULATION IN YEARLING COHO SALMON, ONCORHYNCHUS-KISUTCH

1. Hepatosomatic indices were significantly increased (P < 0.01) in yearling coho salmon fed PCB diets (1.76 ± 0.07) and a mixed PCB-Mirex diet (1.42 ± 0.04) and significantly decreased (P = 0.05) in salmon fed Mirex diets (1.15 ± 0.03) compared with controls (1.27 ± 0.03). 2. Liver lipid reserved (LLI) in PCB-fed fish (99.0 ± 16.6) were significantly increased (P < 0.01) and carcass lipid (34.2 ± 3.0 mg/kg) significantly decreased (P = 0.05) compared with controls (57.6 ± 6.7 for LLI and 50.8 ± 5.9 mg/kg for carcass lipid). 3. The LLI in Mirex-fed coho (55.7 ± 5.6) was similar to the controls although carcass lipid (22.5 ± 5.8 mg/kg) was significantly lower (P < 0.01). 4. Carcass PCB levels in coho fed the high PCB diet (500 mg/kg) were only 3.2 fold higher than coho fed the low PCB diet (50 mg/kg), and Mirex levels in coho fed the high Mirex diet (50 mg/kg) only 6.0 fold higher than in coho fed the low Mirex diet (5 mg/kg). 5. Carcass PCB levels in coho fed a mixed PCB (50 mg/kg)-Mirex (5 mg/kg) diet were significantly higher (P < 0.01) than in fish fed the low PCB diet; carcass Mirex levels in low Mirex diet-fed and mixed diet-fed coho were similar. © 1979.