Long term exposure of marine fish to crude petroleum-I. Studies on liver lipids and fatty acids in cod (Gadus morhua) and winter flounder (Pseudopleuronectes americanus).

1. Total lipids, total phospholipids, lipid class and fatty acids have been studied in the livers of cod and winter flounder from the Northwest Atlantic following long-term exposure to crude petroleum. 2. The levels of free fatty acids and total phospholipids were elevated and triglycerides depleted significantly in the males and females of both species in the experimental groups. 3. The essential fatty acids of C20.5, C22.5 and C22.6 series were significantly altered in the oil-exposed animals. 4. These findings indicate that marine fish, following long-term exposure to crude petroleum, tend to (a) use up their stored energy of neutral lipids and (b) develop changes in membrane structure and function.