Some frequencies of underwater noise produced by fishing boats affecting albacore catch

Acoustic energy introduced by fishing vessels into the water has been measured and analyzed. Catch records have been obtained for those boats whose acoustic characteristics are known. Averaging procedures were applied to catch records to obtain a meaningful average catch rate. This average catch rate is correlated with the spectrum of sound introduced into the water by the boat. A negative correlation between catch rate and frequencies above 1500 Hz has been established. Spectral peaks above 1500 Hz are attributed to propeller shaft bearings.