New orca listening post installed in Puget Sound


On the side it goes with a splash: three ears erect for the sounds of orcas, and the noise that threatens their survival.

Down below, this trio of hydrophones rest on the sea floor, recording the sounds of Washington’s Puget Sound, including endangered Southern Resident orcas. The listening net, developed and deployed by SMRU Consulting, is attached to a buoy that marks its location, about a mile offshore, north of Carkeek Park.

The equipment will be in place for three months, as part of a proof-of-concept experiment to determine if the hydrophones and software can easily pick up killer whale sounds, record underwater noise and share the data via a cellular transmitter, reported the Seattle Times. .

A stock photo of killer whales in Puget Sound with Seattle in the background.

NOAA/Candice Emmons

If all works out, listening networks like this can supplement sightings of orcas by human observers reported on existing networks, already used by Washington state ferries to avoid killer whales. Ultimately, the hope is to deploy multiple networks in Puget Sound to alert ships to the presence of orcas, so they can voluntarily slow their engines to reduce noise or change course.

A slower, more distant ship is a quieter ship – and that counts for Orcs.

With now only 74 orcas in J, K and L pods, the southern residents are some of the rarest whales in the world. There are at least three threats to their survival: the lack of chinook salmon, their favorite food; Pollution; and noise which makes hunting more difficult for them.

Orcas hunt by echolocation – a sophisticated biosonar system with which they locate, hunt and pin their prey. But the noise of boats, ferries and other underwater vacationers masks the sounds they need to hear to hunt.

The Port of Vancouver in British Columbia already has a program in place to calm the waters it shares with whales. The port launched its ECHO program in 2017, which includes a voluntary vessel slowdown in Haro Strait and Boundary Pass.

In 2021, the shipping industry’s cumulative voluntary participation rate was 90% on transits through Haro Strait and Boundary Pass, reducing underwater noise intensity by 50%, according to reports from the ECHO program from the Port of Vancouver and the Vancouver Fraser Port Authority.

A sister program called Quiet Sound, a project of Seattle-based nonprofit Washington Maritime Blue, is in the works.

The Quiet Sound program is in its early stages and includes several efforts, from technology development to the eventual establishment of a slowdown zone in central Puget Sound, said program director Rachel Aronson. Quiet Sound was launched in January with $600,000 from state and federal agencies, ports and foundations.

The program was born out of a recommendation by the orca task force created by Governor Jay Inslee in 2018.

A first step towards a ship-slowing initiative is a field test of hydrophones to help determine when killer whales are in the area. So on a recent morning, Jason Wood, SMRU’s general manager, was on the SoundGuardian, King County’s environmental research vessel, to check out equipment.

Wood worked with Bob Kruger and other crew members to get the device on board, to replace its batteries, and to check it out.

Then Kruger helped lower the equipment, weighing about a ton, into the water with an overhead crane, setting it gently on the bottom, to continue listening. No southern residents have yet been picked up on the device.

Efforts to calm the waters come as the Salish Sea is set to see more boat traffic.

Global supply chain issues and cargo congestion at ports have recently led to a sharp increase in the number of container ships and bulk carriers anchored, including in the Salish Sea.

In addition, 22 new or expanding terminal and refinery projects have been proposed, authorized or recently completed, which will increase marine traffic, according to a 2021 report by Lovel Pratt, director of marine protection and policy for Friends of the San Juans, a non-profit environmental organization.

Twelve of the 22 projects would add at least 2,634 annual vessel transits to and from Salish Sea ports in British Columbia, into the primary summer feeding habitat of Southern Resident Killer Whales.

A total of 46% of the projected increase in marine traffic comes from the expansion of the Trans Mountain Pipeline and the Port of Vancouver’s proposed Roberts Bank Terminal 2, a new container terminal proposed for the Fraser River Delta – where orcas hunt and a crucial Chinook Return race.

If all proposed, licensed and recently built projects in British Columbia are developed, it would result in an increase of at least 25% in large ocean-going commercial vessel traffic, compared to 2020 transits, according to the analysis.

The expansion of Canada’s Trans Mountain Pipeline alone will add 696 annual tug escort transits between the pipeline’s terminus in Burnaby, British Columbia, and the entrance to Juan de Fuca Strait.

With human impacts only increasing, noise is an issue that can be addressed immediately, Wood noted. It takes many years to rebuild salmon runs. PCBs were banned in 1979 but are still bleeding into the environment.

But slowing down a ship can reduce the noise it makes right away. And with enough participants, the effect can make a difference in the orcas’ ability to feed.

“It’s pretty amazing,” Wood said of the success of the ECHO program so far. “This noise reduction converts to foraging time that orcas recover.”

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