Research on noise pollution in Puget Sound underway

It’s a critical time for the endangered southern resident killer whales, and scientists are continuing their work to understand their hunting grounds.

Two new calves have been spotted in the past two months: one with J-Pod, and more recently a calf was spotted with K-Pod, marking the first known baby within K-Pod in more than 10 years.

Despite the positive news, experts say changes are needed to reverse the fortune of the endangered orcas. In fact, many calves in recent years have struggled to survive a full year. 

Scientists have long been tracking the decline of the southern residents' population. Three key issues have been identified: prey availability, contaminants in the water and noise pollution. 

That doesn’t mean that we have a full picture of those issues – when it comes to noise pollution, there are a number of blind-spots. Simply put, it’s hard to track the entirety of Puget Sound, let alone the Salish Sea as a whole.

"It’s dire," said Jason Wood, the managing director of SMRU Consulting. "I’m concerned, specifically about this population."

The Salish Sea may look calm on the surface some days, but underwater, there is a symphony of engine noises ranging from cargo ships to ferries and recreational boats. 

Orcas – which use echolocation to hunt their prey – struggle to feed themselves as their hunting grounds become noisier. 

PREVIOUS COVERAGE: Scientists deploy buoy in Puget Sound to measure noise, risks to orcas

While transient killer whales – also known as Biggs Killer Whales – hunt larger marine mammals, the southern resident orcas feed on salmon. Chasing a single fish costs them a massive amount of energy, and given that a number of salmon species in Washington state are endangered themselves, noise compounds an already precarious situation.

On Tuesday morning out on Sound Guardian, King County’s research vessel, Wood was prepping to remove a series of hydrophones that have been recording audio near Shoreline since February. The initial data, including audio, was relayed via cellphone signals. The raw data removed this week will allow further analysis.

"This is our little effort to stretch the clock out a little bit," said Wood. "We want to give them a chance to recover. Once we understand what’s driving the soundscape better, we can help inform better mitigation strategies – is it one thing or another that’s contributing the most noise pollution."

Wood said he’s hopeful that their data will inform programs like ‘Quiet Sound,’ a new collaborative program launched earlier this year that aims to cut down on noise pollution from large vessels in Puget Sound.

Canada has a similar program that’s already being implemented. ECHO, a voluntary program, has found success within the shipping industry. According to Wood, more than 80% of ships going to the Port of Vancouver are dropping speeds and re-routing when orcas are discovered in the area to reduce noise pollution.


New orca offers hope, as experts race to save PNW's most iconic residents

FOX 13 looks at the progress of the Governor's Orca Task Force, and the current status of the Southern Resident Killer Whales.

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Wood said that Canada is ahead of us, but that it could speed up the work in Washington, since many of the same industry players work on both sides of the U.S.-Canadian border.