Oxygen in Hood Canal reaches dangerous levelsSeptember 17th, 2010 by cdunagan
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.
Tags: Belfair, dissolved oxygen, Hood Canal, Hood Canal Dissolved Oxygen Program, Hoodsport, Jan Newton, Janna Nichols, nitrogen, Ocean Remote Chemical Analyzer, Oxygen, plankton, Potlatch, scuba diving, septic systems, sewage