Underwater Noise Study Begins In Puget Sound

KING COUNTY, WA — Scientists and researchers took to Puget Sound aboard King County's SoundGuardian vessel this month to deploy a new buoy that will help measure underwater noise from boats and provide real-time information on orca sightings.

According to King County, the study is being done pro bono by SMRU Consulting, a marine research firm that has led similar efforts around the world, including the ECHO Program in British Columbia.

For the Puget Sound project, researchers decided to drop the buoy during winter when southern resident orcas are typically in the area in search of chinook and chum salmon. Since orcas rely on sound to hunt and navigate, noise from ships, ferries and other vessels can interfere with their ability to find food.

"Our state-of-the-art research vessel is a valuable asset helping some of the world's leading marine biologists work to protect southern resident orcas," said King County Executive Dow Constantine. "The scientific research they produce will contribute to our collective mission to not only track the health of Puget Sound, but also ensure the survival of its marine life."

The new buoy contains special underwater microphones that measure noise levels from vessels and listen for telltale sounds of orcas on the move, officials said. Both pieces of data are transmitted live through an on-board cell connection and will bolster efforts to quickly engage vessels when orcas are near, so crews can slow down or change course.

Researchers said the buoy also stores the data for later analysis, which will help scientists get a better understanding of long-term trends. The latest study is one piece of the broader Quiet Sound Program, established by the state's Southern Resident Orca Task Force, which has been working to reduce underwater noise since 2018.

"We're grateful to King County for making the SoundGuardian available for this effort," said Jason Wood, the lead scientist for the project. "We hope the data generated by this pilot study will help inform long-standing recovery efforts by organizations such as NOAA, Quiet Sound, Orca Network, OrcaSound, the Whale Museum, OceanWise and others."

Researchers placed the buoy offshore between Seattle and Edmonds, and scientists plan to head back to the area in three months to retrieve the device.

Readers can watch a video of the buoy deployment below: