ADRIFT in the California Current

Pilot whale swimming near drifting acoustic buoy. Photo: NOAA Fisheries/Jay Barlow

Passive acoustic monitoring (listening!) is an effective way to study marine mammals. Towing hydrophones behind a ship gives good geographic resolution, while seafloor hydrophones give good temporal resolution. Our passive acoustic drifting buoys record ~30 days and their low cost allows us to deploy more buoys so that we can improve our study area (in both time and space).

While drifting, the recorders capture ocean sounds including whales, dolphins, fish, and ships. The hydrophones are positioned near animals in the water column which allows them to collect data of the highest quality without affecting animal behavior. These data can be used to study animal populations, potential impact of human activities and environmental change on these protected (and sometimes endangered!) species.

ADRIFT in the California Current

ADRIFT in the California Current employs these drifting buoys to study ocean sound in the California Current Ecosystem.

Drifting acoustic recorder diagram — Drifting acoustic recorders consist of a locator buoy (with radar reflector and satellite transmitters) attached to the recording buoy, with a hydrophone recorder deployed at 100m depth.

These relatively low-cost buoys are easily deployed from most vessels, including: research, fishing, & tourist boats. These buoys are autonomous: once they are deployed, they do not require oversight. They drift at sea, with shoreside monitoring via satellite messenger.

Coordinating data collection with local vessels provides significant cost savings and these valuable partnerships increase community engagement in science.

Drifting acoustic recorders deployed 55 miles off Oxnard, California. — Drifting acoustic recorders deployed 55 miles off Oxnard, California from the M/V Horizon. No scientists were used in the deployment of these hydrophones! Credit: Cary Humphries

ADRIFT in the California Current will emphasize partnerships with local communities as well as public engagement in science. If you have a boat that works off California (>10 nmi offshore) and are interested in learning more about how you can participate in our science, please reach out here: Vessel of Opportunity Survey.

Learn more about ADRIFT by visiting: