An algae bloom in late June killed farmed salmon at aquaculture sites in the Jonesport area, according to the company that runs the sites.
The die-offs occurred at salmon farms run by Cooke Aquaculture USA in Eastern Bay near the towns of Jonesport and Beals, according to company spokesperson Steven Hedlund.
“The marine algae was concentrated by ocean currents and formed an algae bloom,” Hedlund said in an emailed statement. “As the bloom moved into the Jonesport/Beals area it caused periods of low dissolved oxygen in the water column.”
The bloom dispersed naturally after a few days, and Cooke has safely removed and disposed of the dead fish, Hedlund said. The company has notified state officials about the die-off as part of its procedures for responding to deaths.
Jeff Nichols, a spokesperson for the Maine Department of Marine Resources, said the agency doesn’t know how many fish were affected by the die-off, which was reported on June 20.
The agency conducted an assessment June 24 and couldn’t determine the number because the company had been harvesting the fish when the deaths occurred, so some pens were already empty, and not all of the remaining fish had died, Nichols said.
As part of its assessment, the agency collected dissolved oxygen, water temperature and phytoplankton samples, as well as whole fish samples for necropsy, and nothing stood out as notable, according to Nichols.
Another fish die-off was reported at Cooke Aquaculture sites in Maine three years ago, when more than 100,000 salmon were killed when dissolved oxygen levels dropped in their cages. The state ultimately found the company had not violated conditions of its permits in that case.