Effects of Sounds from a Geophysical Survey Device on Fishing Success

摘要

The objectives of the report were to determine the effects of sounds from an acoustic device used in offshore geophysical seismic surveys on the commercial hook-and-line fishery for rockfish on the California coast. The field effort consisted of the Behavioral Experiment and the Main Field Experiment. The objective of the Behavioral Experiment was to determine the threshold at which sounds from an air gun elicit startle responses or other behavioral changes in captive rockfish. A Secondary objective was to make preliminary observations of rockfish response to bait under exposure to air gun sounds. The objective of the main field experiment was to determine the effects of sounds from an air gun on rockfish and its fishery. The experiment primarily investigated effects on Catch-Per-Unit-Effort (CPUE). Rockfish form aggregations over rock pinnacles, and a secondary effort examined effects on the spatial characteristics of the rockfish aggregations. The Behavioral Experiment clearly showed that several species of rockfish give alarm and startle responses to sounds from a single air gun, but swimming behavior returned to normal within less than one minute after stopping the sound pulses.