Acoustic influence of underwater mobile survey vehicles on the soundscape of Pacific rockfish habitat.

Noise produced by scientific equipment during fisheries surveys is largely unstudied, though these sound sources may have an effect on the organisms of interest and on their resultant stock assessments. This paper describes acoustic signatures of two underwater mobile vehicles and accompanying research ships used to survey demersal fishes, and discusses the acoustic contributions of the survey equipment to rockfish habitat. Increases in noise over ambient levels were high, but the majority of sound energy was generated by communication and navigation instrumentation on the ships and survey vehicles, and was out of the expected sensitivity range for fish hearing.