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map of Hood Canal Action Area
Map of Hood Canal Action Area courtesy of Puget Sound Partnership

PSI review finds minimal evidence for human impacts on Hood Canal hypoxia

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An independent review convened by the Puget Sound Institute is featured in findings released by the Environmental Protection Agency and the state Department of Ecology that there is currently “no compelling evidence” that humans are the cause for recent trends in declines in dissolved oxygen in Hood Canal. [Read the Draft EPA and Ecology Report on Dissolved Oxygen Impacts in Hood Canal 09 -14-12.]

map of Hood Canal Action Area
Map of Hood Canal Action Area courtesy of Puget Sound Partnership

The EPA/Ecology draft report relied in part on a May 23rd PSI-sponsored review that surveyed extensive scientific findings on Hood Canal.

“A consistent finding in the available information is that the greatest human impacts to
dissolved oxygen likely occur at the landward terminus of Hood Canal (Lynch Cove),” reads a joint memo from EPA and Ecology regarding the review. “We find that the current impact from human-caused nitrogen releases may be cause for concern, but the available information in this area is uncertain. We hope that by pulling the available information together and identifying the uncertainties, this report helps inform the planning of future studies.”

Scientists have so far been unable to show that nitrogen loading exceeded the legal threshold of 0.2 mg/L in any specific area of Hood Canal, and governing agencies have concluded that a TMDL regulatory process is not warranted at this time based on the current evidence. Concerns remain among experts, however, that population increases in the area could increase nitrogen levels in the future. Local, state and federal leaders will continue to examine ongoing scientific findings, and will convene to discuss a variety of policy and regulatory options once a report is made final, according to the Department of Ecology.

The review was convened by PSI Director Joel Baker and research scientist Andy James, at the request of EPA and Ecology, and featured a report authored by a panel of six nationally recognized experts: Dr. Alexandria Boehm, Stanford University; Dr. Paul Harrison, University of British Columbia; Dr. James O’Donnell, University of Connecticut; Dr. Hans Paerl, University of North Carolina at Chapel Hill; Dr. Ivan Valiela, Marine Biological Laboratory, Woods Hole.

View related documents:

Independent Review Panel Report – 2012-05-23

Independent Review – Appendix A

Independent Review – Appendix B

EPA and Ecology response to comments from the independent review panel 09 -14-12

Draft EPA and Ecology Report on Dissolved Oxygen Impacts in Hood Canal 09 -14-12

Related articles:

Seattle Times: Review of science lets people off the hook for Hood Canal fish kills

Kitsap Sun: Report: No conclusive blame of humans for canal oxygen levels

Kitsap Sun: Researchers consider next steps for Hood Canal