Lack of oxygen in Southwest River causes fish kill

A lack of oxygen in the tidal area of the Southwest River has left thousands of small bait fish dead, according to the province. 

A kayaker reported the dead fish on Tuesday, and officers from the provincial Communities, Land and Environment, and Public Safety and Justice departments investigated. 

"The Southwest River was anoxic at the time," said Wade MacKinnon, manager of investigation and enforcement with Public Safety and Justice.

"The lack of oxygen in the water resulted in a fish kill in the tidal portion of the river. There were live trout found at the head of the river at the time, confirming this was not a pesticide related event."

Nutrients from run off, septic systems and nitrates from farmers fields all kick off the growth of sea lettuce, turning the water a limish green or milky white — along with a horrible smell.

MacKinnon said it's too difficult to estimate how many fish — including mummichogs and blackback flounder — were killed but it "was a large amount of fish." He said the person who reported the incident reported seeing thousands of dead fish.

Anoxic events like this aren't uncommon in the Southwest River, MacKinnon said, adding there have been reports each year since 2007.

According to the Communities, Land and Environment website, there have been 15 waterways and one freshwater pond affected so far this season.

With high temperatures continuing in the forecast, MacKinnon said there is no short term solution.

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