Sediments in Sound among least toxic

By J. Patrick Coolican and Craig Welch
Seattle Times staff reporters

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Puget Sound ranks among the least toxic of all the estuaries and bays in the United States where contamination has been measured, according to the first comprehensive study of chemical and toxic pollutants that have settled on the Sound's floor.

The three-year study, part of a nationwide review of America's coastline, found only 1 percent of 300 sediment samples taken from the Sound were highly polluted with toxic materials or chemicals. Sixty-eight percent of the samples, meanwhile, had clean sediments.

"The good news is degraded sediments in the Sound are not widespread," said Ed Long, formerly with the National Oceanic and Atmospheric Administration, which conducted the study with the state Department of Ecology.

But while scientists were pleased with the results, they noted that 31 percent of the sediment samples were of "intermediate quality" and had some contamination.

"Looking at Puget Sound as a whole, it's nice to know that a large portion of sediments we looked at are high quality, but there are degraded areas," said Maggie Dutch, the lead researcher on the study for Ecology.

Other scientists noted that sediment quality is just one indicator of the health of the Sound. And even the recent findings raise concerns about "hot spots" in industrial areas near Seattle, Bremerton, Tacoma and Everett.

"The size of Puget Sound makes the problem look smaller because (contamination) is concentrated in urban bays. But we do have significant areas ... we need to clean up," said John Dohrmann of the Puget Sound Water Quality Action Team, a state agency.

Sediments offer habitat for critters that provide food for fish — such as English sole, flounder and juvenile salmon — that can spend a month feeding on insects in an estuary before heading to sea. Contamination can work its way up the food chain.

For years, scientists have measured mercury, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in industrial and developed portions of the Sound. But until now, no one had measured how widespread such contamination is.

Scientists collected samples from randomly chosen spots covering 2,363 square kilometers, from Canada to Hood Canal and south Puget Sound. They tested for numerous chemicals, performed toxicity tests and examined the health of communities of invertebrates in sediment.

Although 53 percent of the total survey area had concentrations of chemicals that exceeded a state or NOAA guideline, that dropped when four nontoxic and ubiquitous chemicals were discounted: nickel, benzoic acid, phenol and 4-methyl phenol. Then contamination tapered off, suggesting it was highly concentrated in a few areas that could be cleaned up.

Unlike New York and Boston harbors or the bays of Southern California, the Sound was relatively free of dangerous toxins, Long said. He compared it to Florida's Tampa Bay, a large central waterway that's clean but has nasty spots in harbors and near the city.

The study is evidence that Puget Sound regulators have "largely turned the corner on waste management" since World War II, Long said, when toxins were regularly spewed into the waterway. But it's tough to draw conclusions.

"If you try to draw a link between contaminants and the overall health of the Sound ... I'm not sure you can do that," said Alan Mearns, also with NOAA.

Key indicators of the Sound's health are mixed. Chinook salmon and many groundfish stocks are in decline, as are orca numbers and, in many areas, eelgrass beds. Shoreline pollution in mussels and other species may be on the rise, including contamination from PCBs and PAHs. Meanwhile, bulkheads and seawall barriers that starve beaches of new sand and gravel are increasing by up to two miles a year, with 70 percent of the shoreline already behind some sort of barrier.

Still, there are more shellfish beds being reopened than closed due to bacterial contamination, water quality is high at 73 percent of fresh-water monitoring stations, fecal coliform is in decline in a few of the polluted river mouths and harbor seals appear to be rebounding.

Craig Welch: 206-464-2093 or cwelch@seattletimes.com; J. Patrick Coolican: 206-464-3315 or jcoolican@seattletimes.com

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