The effects of hydrocarbon pollution from a two‐stroke outboard engine on the feeding behaviour ofLythrypnus dalli(Perciformes: Gobidae)

Abstract

Feeding behaviour (time of attack on flake fish food) in Lythrypnus dalli was measured under pollution concentrations of 2.1 and 4.01mgl -1 total extractable material produced by a twostroke outboard engine. The variance of the times increased in pollution versus control treatments for both concentrations. No significant difference was found between the mean times of the control and 2.1 mgl -1 pollution treatments. A significant difference was found between the mean times of the control and pollution treatments for two different tests at 4.01 mgl -1 . The combination of the increase in mean time of food attack and the increase of variance indicates that pollution concentrations lower than LD50 levels change feeding behaviour, and thus may indirectly effect the survival of the organism.