Lethal oxygen levels in Hood Canal could kill fish this summer

Tests show that the amount of dissolved oxygen in the fjord has dropped to near-lethal levels -- and the problem is likely to get worse this summer, state officials said yesterday.

"The prediction that we're getting is that there's a pretty high likelihood that we will have a fish kill this summer again," said Mary Lou Mills, marine ecosystem manager with the state Department of Fish and Wildlife.

Oxygen levels this spring in Hood Canal were the lowest measured at this time of year in five decades, according to data from the state Ecology Department. Based on past trends, the levels will continue to drop in the weeks ahead.

Summer sunshine typically triggers the growth of algae. When the plants die, they sink and decompose -- a process that consumes oxygen needed by fish and other marine life.

During the past two years, low oxygen levels have been responsible for three major fish kills in the canal. The most recent kill occurred in October, when about two dozen species of fish washed up on beaches.

Rockfish and six-gill sharks that love the dark depths crammed themselves into the top 20 feet of water, where the little oxygen that's present still could be found, state scientists said. Ling cod and reclusive wolf eels were spotted in the shallows, noticeably in distress.

The Puget Sound Action Team, a state agency, recently estimated that up to 300 tons of pollutants are being released into the canal each year, helping fuel the algal blooms. Sewage released from aging septic systems accounted for the most pollution, followed by farm manure and salmon carcasses that were dumped after being harvested for roe.

The problem is made worse by poor circulation in the 60-mile-long fjord. The upper layers that have more oxygen tend not to mix well with deeper, oxygen-depleted water. A flush of fresh water and exchange with ocean water can improve water quality. But that happens more commonly in the winter months.

Other areas that suffered from low oxygen levels, such as Chesapeake or Delaware bays, have improved once the pollution was curbed, said Jan Newton, senior oceanographer with Ecology and faculty member at University of Washington.

But there is concern about the long-term damage being caused to marine life.

"If things improve, will it be of a timeliness that is useful for the rockfish, for the sea cucumber, for the other things that are feeling the effects of the low oxygen?" she asked.

Fishing for most species in the canal has been prohibited since February, and state Fish and Wildlife officials are expected to make the ban permanent. Fishing for salmon, shrimp and shellfish is allowed.

State and federal governments have taken action to try to solve the problem. They've funded research that is ongoing and this month began soliciting proposals from businesses, organizations, schools, governments and tribes for $600,000 worth of projects that will reduce pollution.

The action was triggered when officials realized the situation was not correcting itself as it had in the past.

The poor water quality has undone some of the recent gains made in the canal's fish populations. Sund Rock, a spot north of Hoodsport, was put off-limits to fishing about a decade ago. Since then, researchers have seen long-lived species, such as rockfish, re-establish themselves in the area.

"The population has been stable and increasing a little bit," said Fish and Wildlife biologist Wayne Palsson.

"It's certainly sad to see this big mortality. The fact that it's getting worse and maybe human-related is very sad."

GETTING INVOLVED

To report fish kills, algal blooms or other problems in the water, call the state Department of Ecology's hot line at 800-OILS-911.

To apply for money for projects to help fix Hood Canal's low-oxygen problem, call Stephanie Lidren, Puget Sound Action Team, at 360-725-5441 or go to www.psat.wa.gov/Programs/hood_canal.htm.

For information on Hood Canal, go to www.prism.washington.edu/hcdop/index.html.

P-I reporter Lisa Stiffler can be reached at 206-448-8042 or lisastiffler@seattlepi.com

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