Tag Archives: Oxygen

Oxygen in Hood Canal reaches dangerous levels

I hate to be the voice of doom, but low-oxygen conditions in Hood Canal have never been worse — if you can believe the data gathered since the 1950s, alongside more intense monitoring the past several years.

In the southern portion of Hood Canal, you only need to go down about 30 feet to begin to see stressful oxygen levels in the range of 2 milligrams per liter. For current conditions at Hoodsport, go directly to the Hood Canal Dissolved Oxygen Program’s website, which lists data sent back from the Ocean Remote Chemical Analyzer (ORCA).

Sea creatures are beginning to show signs of stress, according to scuba diver Janna Nichols, who described her findings to me Wednesday after a dive in Hood Canal. She talked about fish “panting” as their gills moved in and out rapidly. Some fish, shrimp and other sealife had moved into shallower water. Watch Janna’s video of a wolf eel and other visuals she captured on the dive.

When low-oxygen conditions are that close to the surface, the danger is that a south wind will blow away the surface layer and bring low-oxygen water right to the surface, leaving fish with no place to go.

Of course, I have no desire to see a massive fish kill, but we already know that fish are probably dying in deep water due to the stressful conditions. I collect this information and offer these reports so that people can alert researchers when something happens. Being on the scene when fish are dying could provide important information about the nature of the low-oxygen problem. For details, please check out my stories in the Kitsap Sun Sept. 7 and Sept. 15 as well as the more technical report from Jan Newton on Sept. 7 (PDF 320 kb).

The phone number to report fish kills or oil spills is (800) 258-5990 or (800) OILS-911

If you haven’t heard, the worst low oxygen conditions normally occur in the fall after a summer of burgeoning numbers of plankton, encouraged by nitrogen and sunlight. By fall, much of the plankton has died and dropped to the bottom, where decay consumes the available of oxygen.

While there are plenty of natural sources of nitrogen in Hood Canal, computer models have demonstrated that human inputs from septic systems and stormwater can push things over the edge in the fall.

Officials are hoping that a new sewage-treatment plant in Belfair will begin to reduce the inputs of nitrogen into Lynch Cove. Another treatment plant is being planned in Potlatch. Stormwater upgrades also are being proposed for Belfair and other areas.

In addition to the low-oxygen problem, Hood Canal was closed to the harvest of oysters after people became sick from vibriosis, a natural bacteria that multiplies in warm conditions. See Kitsap Sun story Sept. 10 and Washington Department of Health maps.

The orange triangles represent this year's composite oxygen levels for the south half of Hood Canal. The latest reading, near the end of August, is the lowest ever seen.

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Report notes oxygen troubles in Northwest waters

Low-oxygen problems in Hood Canal and along the Washington-Oregon Coast are highlighted as “case studies” in a new federal report regarding the growing number of “dead zones” across the United States. See “Scientific Assessment of Hypoxia in U.S. Coastal Waters” (PDF 2.7 mb).

Incidents of hypoxia have increased 30-fold since 1960, according to the report. The new federal review describes the causes of hypoxia, discusses past and ongoing research efforts and lays out policy recommendations to deal with the problem. Eight troubled waterways are reviewed as “case studies.”

In a news release (PDF 116 kb) accompanying the report, Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration, offered these comments regarding hypoxia and the seasonal low-oxygen area off the coast of Washington and Oregon:

“The report shows good progress on research into the causes of hypoxia and the specific management requirements to restore systems such as the Gulf of Mexico and Chesapeake Bay, but we still have a long way to go to reduce this environmental threat. The discovery of a new seasonal hypoxic zone off the coast of Oregon and Washington that may be linked to a changing climate emphasizes the complexity of this issue.”

That West Coast dead zone is now ranked the second largest in the United States and the third largest in the world. Federal officials say there may be serious consequences to the ecological health of the region.

Lisa Jackson, administrator of the Environmental Protection Agency, said the EPA is proud to have played a role in the research leading up to the report:

“These growing dead zones endanger fragile ecosystems and potentially jeopardize billions of dollars in economic activity. This science can be the foundation for measures that will preserve our waters and reverse the trend, including innovative, watershed-based solutions to this challenge.”

Mike Lee, a reporter with the San Diego Union-Bulletin, interviewed Tony Koslow, who studies low-oxygen areas at the Scripps Institution of Oceanography.

“This is a large phenomenon not due to nutrient outflows” from land, Lee quoted Koslow as saying. “The big question is, ‘Is this due to climate change?’ ”

As the oxygen-rich surface layers warm up, they mix less with colder layers down deep where oxygen levels are low, Koslow said. Global climate models predict that the oxygen levels in deep oceans will decline 20 to 40 percent the next century.

“There are substantial ecosystem concerns,” Koslow said. “A number of species that live in the deep ocean are very sensitive to changes in oxygen levels. These species — although they are not of commercial interest — are prey to squid, fish, marine mammals and seabirds, so changes in oxygen will have repercussions throughout the food web.”

The report suggests these policy actions:

  • Develop and implement cost-effective and scientifically
    sound nutrient reduction strategies to achieve healthy water
    quality in rivers, lakes and coastal waters.
  • Improve ecosystem models to assess how hypoxia
    affects commercially important fish populations in order to
    refine management strategies to protect coastal economies.
  • Improve scientific understanding for emerging sites such
    as the Oregon and Washington shelf, where hypoxia may be
    driven primarily by events linked to climate change. This
    knowledge will help managers mitigate impacts on natural
    resources and coastal economies.
  • Expand stream and river monitoring to document extent
    and sources of nutrients and progress in achieving management
    goals. This can lead to more strategic and effective targeting of
    nutrient reduction actions.
  • More systematically monitor oxygen levels in coastal
    waters using new technologies and observing systems. This is
    critical for forecast model development, fisheries management,
    and determining nutrient reduction success.

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Ocean conditions are playing tricks on Hood Canal

Hood Canal continues to baffle us humans with scenarios that we have never seen before, as I outline in a story in today’s Kitsap Sun. The canal’s latest failing is to forget that, by this time of year, there is supposed to be a layer of dense, oxygenated water lying on the bottom.

I’m being facetious, of course, about how the canal is “supposed to” behave. The fact that researchers are seeing something for the first time in Hood Canal does not mean it has never occurred before. And the fact that natural conditions can be highly variable does not mean that human inputs of nitrogen have no influence over the life or death of sea creatures.

As it has been explained to me, in years when natural conditions push Hood Canal close to the danger zone, human factors can push it over the edge. So limiting nitrogen flowing into the canal can make a real difference, especially in years when natural factors gang up to deplete the oxygen supply.

As I explained in some detail in today’s story, conditions in Hood Canal the past 18 months have been interesting to watch. Early in 2009, the average dissolved oxygen in the canal was near record highs, then the level dropped rapidly to measurements at or below what is normally seen in the fall. Over the winter, the levels never came back up — which is something never observed before. Now the levels are beginning to drop again, and we don’t know how low they will go.

What is encouraging about all the monitoring and studies conducted the past few years is that we can actually measure what is happening in real time, and we are in a better position to explain why the canal is responding as it does. Now if only we could predict the weather and ocean conditions, which seem to have a mind of their own …

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