Puget Sound population growth puts water quality in jeopardy
Bobbing like corks on the water near the Narrows Bridge, crew members aboard the research vessel Skookum plunge 300 pounds of testing equipment into the water.
Their purpose: to take water quality readings from one of 80 sampling stations used in the state Department of Ecology's study of dissolved oxygen in South Sound.
Above them, contractors put the finishing touches on the new Narrows Bridge, which is being built to keep up with the same kind of population growth that prompted Ecology's South Sound study in the first place.
Researchers are trying to answer the question: Is South Sound overloaded with nutrients to the point that parts of it could go the way of lower Hood Canal, where oxygen depletion is stressing and killing marine life? Unfortunately, the emerging answer appears to be "yes."
"The truth is South Sound is vulnerable to low dissolved oxygen due to poor water circulation, population growth and nutrient loading," said Bill Dewey, a spokesman for Shelton-based Taylor Shellfish. "Nutrients in South Sound are a serious problem."
Ecology launched the $400,000 South Sound dissolved oxygen study in October to pinpoint problem areas in the marine waters that border Mason, Thurston and Pierce counties, track potential pollution sources and offer a road map to curb the flow of nutrients into the water.
The study is part of Gov. Chris Gregoireís Puget Sound Initiative, an ambitious and costly plan to make Puget Sound much healthier than it is today by 2020.
The primary cause of oxygen depletion appears to be an excess of nitrogen and other nutrients in parts of the Sound, which causes algal blooms to flourish. When they die and decay, they rob the water of oxygen.
Sources of nitrogen pollution in South Sound include discharges from wastewater treatment plants, septic systems, fertilizers and animal wastes. Some of it enters Puget Sound through sewage discharge pipes and some comes via stormwater runoff.
Nitrogen also is part of the natural ecosystem, noted Ecology marine researcher Mindy Roberts. For instance, alder leaves that drop into streams flowing into Puget Sound and Hood Canal deliver nitrogen; nitrogen also arrives in Puget Sound from the ocean.
"A little bit of nitrogen is a good thing," Roberts told a recent meeting of the House Select Committee on Puget Sound. "Too much is not."
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Area's population growth puts water quality in jeopardy
