by Dr.Carl Shipley, PhD,
I feel the Kitsap Sun’s April 13 article on the role of septic systems in Hood Canal fish kills is misleading in important respects.
To the average reader the headline, “Septic systems blamed in fish kills,” suggests septic failures are a major culprit in the periodic low-oxygen conditions responsible for fish kills. However, research cited by the article clearly states that we don’t have good measures of septic system influence on nitrogen in Hood Canal, noting that accurate estimation of this “poses several problems.”
We do, however, have good evidence suggesting that septic systems may not be a major cause of low-oxygen events. A well-funded, 2008 study by the Battelle Research Institute, using sediment core samples dating back hundreds of years, revealed that the kind of low-oxygen events responsible for fish kills were, on average, worse in Hood Canal before European settlement than they have been after that settlement.
Your article also describes fish kills as “massive” when, in fact, the most recent kill, in 2010 (the first such event since 2006), involved observations of a total of about 200 dead fish on Hood Canal beaches.
An Internet search reveals that the kinds of episodic low-oxygen events seen in Hood Canal occur in fjords around the world. I am not suggesting we ignore fish kills but, in an era of limited funds for environmental projects, we need to keep in mind that they are largely a natural phenomenon.