In a new study, Integral Consulting and its partners from Oregon State University are investigating how seismic surveys might affect fish and invertebrates in a research project funded by the National Science Foundation (NSF), the Bureau of Ocean Energy Management, and Oregon SeaGrant.
Spanning more than 600 miles, the Cascadia Subduction Zone is long fault that stretches from Northern Vancouver Island to northern California. This month, an NSF-sponsored geophysical survey is being conducted in that zone using high-energy air guns as an acoustic source. The study provides a unique opportunity for researchers worldwide to understand the behavioral responses of fish to anthropogenic sounds.
“As the ocean becomes ever noisier, we need to understand how sounds derived from human activities may alter the behavior of animals in the marine environment,” explains Kaus Raghukumar, Ph.D., Integral scientist and co-investigator on the project.
The project, awarded to Oregon State University earlier this year, will investigate the potential effects of loud, impulsive noises—their pressure pulses and associated particle motion—on fish and invertebrates. During the study, Integral will deploy an acoustic vector sensor array, known as NoiseSpotter™, in Redfish Rocks Marine Reserve to measure the particle motion component of the acoustic disturbance from the seismic survey. Team members will assess the behavioral responses of rockfish, lingcod, and Dungeness crab in the reserve to seismic blasts using acoustic telemetry, tracking both 2-dimensional movements and acceleration of all species.
Most underwater acoustic studies focus on sound pressure, and investigations have often overlooked the sensitivity of fish and invertebrates to particle motion. Further, few data are available on the in situ individual responses of temperate fishes and invertebrates to seismic surveys, particularly the particle motion aspect. This event provides a unique, statistically robust opportunity to characterize ocean noise and investigate the responses of nearshore northeast Pacific species to substantial and sudden alterations to the regional soundscape.
The novel results of this project will advance understanding of the energetics of acoustic propagation in nearshore environments and the responses of animals to anthropogenic activities. Results will be published in relevant journals and communicated to the public during local events at marine science centers in Oregon.