How do we address Hood Canal’s oxygen deficit?

Five years ago, a lot of people were wondering why fish were dying more often in southern Hood Canal during the fall.

Researchers knew that Hood Canal was sensitive to nitrogen. In other words, when nitrogen was introduced to the canal during summer months, nearly all of it was taken up by plankton, which grew into large blooms. When the plankton died, they sank to the bottom, where bacterial decay sucked up the available oxygen.

Beyond that, the questions were numerous: What were the most critical sources of nitrogen affecting the low-oxygen problem? What role does weather and water circulation play? And what can humans do to help the problem — or at least keep it from getting worse.

After a five-year, $4-million study, these questions can be answered with some certainty, as I point out in a story in Sunday’s Kitsap Sun. Now it is time for researchers to convey this information to political leaders and the public, as the Hood Canal Coordinating Council prepares a plan of action.

Scott Brewer, executive director of the HCCC, told me that the eventual plan is likely to include a suite of actions to address nitrogen inputs to the canal, particularly from human sources.

Five or more years ago, some people were anxious to solve the low-oxygen problem, and some steps were taken. A sewage-treatment plant for Belfair was pushed forward. Everyone in the Hood Canal watershed was encouraged to reduce their use of lawn fertilizers. Also, the Skokomish Tribe ordered its fishermen to quit dumping low-value salmon carcasses into Hood Canal, where decay of the fish could add to the oxygen deficit.

But some ideas proposed as solutions were overkill, as many of us believed at the time and five years of study bears out.

Some people seemed rather stubborn about the entire low-oxygen issue, saying they would not even believe there was a problem until studies proved that humans play a role in the health of Hood Canal. (Given some reader comments on my Sunday story, it appears that some now believe the research should not have been done at all or perhaps should not have cost so much.)

After following research developments over the past five years, I can say that we know a great deal about how Hood Canal operates and where the problems lie. The monitoring buoys, which inform us about conditions hour by hour, have proven invaluable in understanding the system. Volunteers who go out in all weather have filled in the blanks for areas not covered by the buoys, and we owe them our thanks.

Still, there will always be uncertainty, as with any scientific endeavor.

For those who wish to learn more and help with solutions — and even those who want to block further efforts — check on the website of the Hood Canal Dissolved Oxygen Program. Meanwhile, I’ll do my best to keep everyone informed as the planning moves forward.

Data from the monitoring buoy at Hoodsport (below) show how surface oxygen levels dropped into the danger zone twice in the last 30 days. Oxygen levels at the surface are currently in a healthy range, but bottom fish cannot yet return to their normal depth. A layer of low-oxygen water remains a threat if south winds were to blow the surface waters away.

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