Underwater microphones deployed to protect orcas from vessels in Salish Sea
A new method of whale detection will help protect cetaceans from ship disturbances and collisions in B.C.'s Salish Sea, an ocean conservation group announced on Thursday.
Vancouver-based Ocean Wise said automatic detections by hydrophones — underwater microphones — will be used to alert nearby commercial mariners of orcas in the area via the group's Whale Report Alert System.
Such alerts will help mariners determine when to slow down, reroute, or stop to avoid whale disturbance and injury, Ocean Wise said in a news release Thursday.
The hydrophones will be based at the Boundary Pass Underwater Listening Station, south of Saturna Island in a busy shipping lane that orcas frequent.
The underwater station, operated by JASCO Applied Sciences, was commissioned in 2020 by Transport Canada and the Port of Vancouver to detect and track endangered whales and to measure underwater noise emissions of thousands of commercial vessels. But the hydrophones are new and as of Thursday, Ocean Wise said they had received several alerts. Any mariner who is signed up for the whale report system receives the alert.
The station is also within the designated critical habitat of the endangered southern resident killer whales.
On Wednesday, a study by Raincoast and a team of international scientists found that the risk of extinction for this critically endangered species has accelerated, with a worst-case scenario of the species being wiped out in as little as 40 years.
Southern resident killer whales live in the Pacific Ocean off the coasts of B.C., Washington, Oregon and California. There are only 75 left.
Alex Mitchell, manager of Ocean Wise's Whale Report Alert System, said there is no mandate for how mariners use the data they receive. However, mariners do not want to hit whales for many reasons, he said, and this will allow them to make decisions such as slowing down or changing course.
The new hydrophones can detect orca sounds within a two-kilometre range. They don't yet detect the sounds of humpback whales, but Mitchell said the technology will eventually be expanded for different species.
“If I was a mariner, I would treat all killer whales the same and expect that they are southern residents and want to take action based on the presence of killer whales. So this new integration of new data means that we have more data on presence of killer whales and therefore that heightens our ability to be able to avoid interactions with them whilst we're at sea,” he said Thursday.
“This is a first step in disseminating this information in real time out to mariners, and hopefully in the next year, two years, we'll have a lot more information flowing into this system.”
He said local mariners who guide large shipping tankers into the Port of Vancouver use the alert system, as does B.C. Ferries.