ABOARD THE SOUNDGUARDIAN, Puget Sound — Over the side it goes with a splash: three ears pricked for the sounds of orcas, and the noise that threatens their survival.
In the deep, this trio of hydrophones rests on the sea bottom, recording the sounds of Washington’s Puget Sound, including endangered southern resident orcas. The listening array, developed and deployed by SMRU Consulting, is attached to a buoy that marks its location just about a mile offshore, north of Carkeek Park.
The equipment will be in place for three months, in a proof-of-concept experiment to determine if the hydrophones and software can readily pick up the sounds of orcas, record underwater noise and share the data through a cellular transmitter, The Seattle Times reported.
If it all works, listening arrays like this can supplement orca sightings by human observers reported on existing networks, already being used by the Washington State Ferries to steer clear of the killer whales. Ultimately, the hope is to deploy multiple arrays in Puget Sound to alert ships to the presence of orcas, so they may voluntarily slow their engines to cut their noise, or change course.
A slower and more distant ship is a quieter ship — and that matters to orcas.
With now only 74 orcas in the J, K and L pods, the southern residents are among the rarest whales in the world. There are at least three threats to their survival: lack of Chinook salmon, their favorite food; pollution; and noise that makes it harder for them to hunt.
Orcas hunt by echolocation — sophisticated biosonar by which they locate, chase and nail their prey. But the noise of ships masks the sounds they need to hear to hunt.
The Port of Vancouver in British Columbia already has a program in place to help quiet the waters it shares with whales. The port in 2017 launched its ECHO program, which includes a voluntary slowdown for ships in Haro Strait and Boundary Pass.
In 2021, the cumulative voluntary participation rate by the marine transportation industry was 90 percent on transits in Haro Strait and Boundary Pass, reducing underwater noise intensity by 50 percent, according to ECHO program reports by the Port of Vancouver and Vancouver Fraser Port Authority.
A sister program called Quiet Sound — a project of Washington Maritime Blue, a Seattle nonprofit — is in the works.
The Quiet Sound program is in its initial stages and includes several efforts, from technology development to eventually implementing a slowdown zone in central Puget Sound, said Rachel Aronson, the program director.
Quiet Sound launched in January with $600,000 from state and federal agencies, ports and foundations. The program grew out of a recommendation from the orca task force empaneled by Gov. Jay Inslee in 2018.
A first step toward a vessel-slowdown initiative is a field trial for the hydrophones to help determine when orcas are in the area. So on a recent morning, Jason Wood, managing director at SMRU, was out on the SoundGuardian, King County’s environmental research vessel, to check on the equipment.
Wood worked with Bob Kruger and other crew members to haul the device aboard, replace its batteries and check it over.
Then Kruger helped lower the equipment, weighing about a ton, back into the water with an overhead crane, setting it gently on the bottom. No southern residents have been picked up on the device yet.
Efforts to quiet the waters come as the Salish Sea is poised to see more vessel traffic. Issues with the global supply chain and cargo congestion at ports recently have caused a big increase in the number of container ships and bulk carriers sitting at anchor, including in the Salish Sea.
In addition, 22 new or expanding terminal and refinery projects have been proposed, permitted or recently completed that will increase vessel traffic, according to a 2021 report by Lovel Pratt, marine protection and policy director for Friends of the San Juans, an environmental nonprofit.
Twelve of the 22 projects would add at least 2,634 annual vessel transits to and from Salish Sea ports in British Columbia.
