A new paper finds endangered orcas face yet another challenge, human pathogens in the marine environment.
Pity the poor orcas.
They’re already stressed from pollution, noise from vessel traffic and lack of food because of declining salmon runs. And now scientists, in the first study of its kind, have identified a fourth risk factor: pathogens that could hurt the endangered Southern Resident Killer Whale population — possibly from human sewage.
Down to 78 animals, the orcas are in an uphill battle for survival. In research over four years, scientists found yet another reason why, detected in their exhaled breath.
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In their paper published Friday in Nature’s Scientific Reports, scientists detailed their research using petri dishes extended on 25-foot-long poles to capture samples of orcas’ breath as they came to the surface in the wild and exhaled.
The whales exchange as much as 85 percent of their lung capacity when they come to the surface to breathe, so the dishes got a blast direct from the microbiome within the creatures’ lungs.
What scientists discovered in 26 samples from orcas around the San Juan Islands was a bevy of microbes that they analyzed and screened for antibiotic resistance. They were looking for evidence of human activity and in particular waste seepage into the marine environment. That’s important because the pathogens can sicken both orcas and people.
One possible source of the pathogens is human sewage. “It is noteworthy that within 30 miles of the study area the city of Victoria, B.C., does not have a secondary sewage treatment facility, and instead discharges primary treatment product from the resident population of approximately 360,000 to the Salish Sea,” the scientists wrote.
“A correlation may exist between the lack of secondary treatment for sewage entering the Salish Sea and the presence of antibiotic resistant bacteria within … breath samples,” the scientists wrote.
Linda Rhodes, research microbiologist of the Northwest Fisheries Science Center in Seattle and an author of the paper, said orcas are susceptible to many of the same diseases we are, which makes cleaning up effluent going into the Salish Sea all the more important.
“We are releasing our waste products into the Sound … and our pathogens pose a threat to them,” she said.
Secondary sewage treatment kills many more pathogens in sewage, and while it is planned for Victoria, the controversy over its lack has raged for decades in Cascadia. Washington Gov. Jay Inslee and King County Executive Dow Constantine wrote the premier of British Columbia in June 2014 chastising the government for not yet upgrading their treatment beyond rudimentary primary screening and discharge.
The Capital Regional District of southern Vancouver Island now is launching work on a state-of-the-art plant to be completed by 2020.
The issue is a sore point right now for King County as crews work hard to recover from a disastrous flood in the region’s largest wastewater treatment plant on Feb. 9.
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Since the flood, the West Point plant was until this week reduced to rudimentary treatment and in high-water events was passing about 235 million gallons of untreated wastewater, including about 30 million gallons of raw sewage, into Puget Sound through its emergency bypass.
The plant also has on a daily basis since the flood been discharging water far less clean than its permit requires, including tons of solids per day into Puget Sound because its primary treatment system was crippled, and its secondary treatment plant offline.
Working around the clock since the flood, crews have made major progress toward normal operations, Christie True, director of King County Natural Resources and Parks, said this week. The target date for resuming normal operations is April 30.
Meeting that goal depends in part, though, on beneficial microorganisms within the secondary treatment system.
Wastewater managers determined this week that microbial activity in the secondary system is too lackluster to rely on. Instead, that system must be reseeded from the South Plant at Renton, a delicate process that takes weeks to finesse. How well the microorganisms are responding and returning to health won’t be known for some time.
Meanwhile, the county this week restored one of its primary tanks to full operation, a major milestone in the recovery process that already has cut by half the tons of solids pouring into Puget Sound. The second tank is expected to be operational soon.
Causes of the flood are under investigation, but so far equipment failures including float switches and pumps are implicated.
King County has invested hundreds of millions of dollars of ratepayers’ money in upgrading to secondary treatment precisely to better protect the ecology of Puget Sound. Even more money is being spent to control overflows of untreated wastewater into the Sound during heavy rain.
The study shows how linked people are to the water and the animals in it, something that can be easy to forget, said Joe Gaydos of the SeaDoc Society, a marine conservation nonprofit. “We are way more connected to these guys than we think,” Gaydos said of orca whales. “We have this artificial separation in our minds.
“We are just beginning to understand how closely tied our health is to their health.”