Avoidance from petroleum hydrocarbons by the cod (Gadus morhua)

In laboratory experiments cod was presented a choice situation\nbetween different concentrations of petroleum hydrocarbons, appearing\nas "water soluble fraction" and emulsified droplets derived\nfrom Fuel Oil No. 2. In most experiments, the fishes seemed to\navoid water containing hydrocarbons, though some fishes for periods\nwas indifferent also to considerable contaminated water. The\nover all results indicates that a majority of the fishes avoided\nwater containing total hydrocarbons down to 50-100 ug/l sea water.\nAt still lower concentrations, the behavioural response most often\nseemed indifferent.