For pinnipeds, he explains, the noise is like fingernails on a chalkboard.Īfter years studying the effects of sound on marine mammals, Götz, along with the TAST’s main co-developer, Vincent Janik, also at the University of St Andrews, found that a sound with a frequency between 500 and 2,000 hertz will startle a seal but is largely outside the sensitive hearing ranges of other wildlife such as salmon and whales. “If a sound has certain properties, then it triggers a muscle contraction - a flinch,” he says. The TAST represents an exciting new advancement in pinniped deterrents because it takes advantage of something called the acoustic startle reflex, says Thomas Götz, a marine mammal researcher at the University of St Andrews in Scotland who co-created the technology. Bogaard plans to continue testing the device at Tumwater Falls Park, south of Olympia, another salmon choke point. The project, however, was shut down in the summer of 2022 because the experimental protocols were not compatible with other management measures being used at the Ballard Locks.
She found that while the number of seals in the area remained the same, they stayed farther from the fish ladder. Food is the ultimate payoff, and that’s why it’s been a near impossible thing to stop.”īut Bogaard says that a new device, called the Targeted Acoustic Startle Technology (TAST), seems to have worked where other approaches failed.īetween 20, Bogaard tested the TAST at the Ballard Locks. “The big challenge,” says Andrew Trites, a pinniped researcher at the University of British Columbia, “is you’re trying to stop from doing something that such a positive reward, which is getting to eat. The issue has been so long-standing that some conservation managers argue for measures as extreme as culling problematic pinnipeds. (The pinger, it turned out, had more of a dinner-bell effect.) They have even fed the pinnipeds fish laced with lithium chloride, a noxious but not deadly chemical, and continue to use firecracker-like seal bombs. They installed a fiberglass killer whale that bellows predatory calls and used a device known as a pinger to try to scare the pinnipeds away. To protect the fish, conservation managers have been trying a variety of methods to shoo them away. “They figured out it’s an all-you-can-eat buffet.”įor decades, pinnipeds have been congregating at the Ballard Locks to gorge themselves on fish populations already stressed by pollution, habitat loss and overfishing. “Pinnipeds - seals and sea lions - are way smarter than I think we give them credit for,” says Laura Bogaard, an ecologist with Oceans Initiative, a Seattle-based nonprofit research organization.
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