DEP staff investigating the incident found that the dissolved oxygen levels in water outside the pens were above the minimum limits, and that the pens where the fish died were not overcrowded.
On Monday, the Maine Department of Environmental Protection (DEP) issued a press release saying that Cooke Aquaculture did not violate the conditions of its permit when more than 100,000 fish died at one of the company’s salmon farms last month.
Although Cooke is not required to report mortalities to the DEP, on Friday August 27, the company notified state officials that they had removed and disposed of carcasses and cleaned the net pens at each site.
According to the press release, the mortalities in August for Black Island were 28,212 and at Black Island South, 87,607.
DEP staff investigating the incident found that the dissolved oxygen levels in water outside the pens were above the minimum limits, and that the pens where the fish died were not overcrowded. The agency further said that it found no evidence of excessive fouling or waste on the pens’ submerged nets.
On September 23, Enforcement and Compliance staff met to review the permit requirements and the data submitted by Cooke to the Department. As a result of that examination, DEP did not identify any permit violations or violations of the Clean Water Act in relation to the reported fish kill.
A spokesman for Cooke said last week that such mortalities are unfortunate and happen naturally on occasion in aquaculture farming, and that the fish that died were only roughly 10 per cent of all the fish being cultivated at Black Island.