FRENCHBORO — State regulators said they have found no infractions connected to a mass fish die-off of more than 115,000 salmon at a fish farm near Frenchboro in August.
Cooke Aquaculture discovered the large number of salmon had died at its Black Island net pen sites on Aug. 16, according to the Department of Environmental Protection. The die-off was reported to the agency on Aug. 27. The carcasses were disposed of and the pens were cleaned before investigators arrived a few days later.
DEP found no evidence of excessive fouling, according to a statement from the agency on Monday. Visibility was limited to about 5 to 8 feet and the pens had already been cleaned within the last week.
A Cooke spokesman previously said the die-off was believed to be because of uncommonly low dissolved oxygen levels in the fish cages.
Though not required to, Cooke provided dissolved oxygen data to the state and largely found that the sites were within level limits. There were low-level readings at a single net pen site on Aug. 15 and 16.
All pen densities reported to the department during June, July and August were within permit limits, according to the DEP.
After the investigation, enforcement and compliance staff met and found no violations of the permit or Clean Water Act.
Emails between DEP officials that were obtained and released by Protect Maine’s Fishing Heritage Foundation, a group that has been advocating against American Aquafarms, showed that officials were skeptical that the levels of dissolved oxygen would result in the death of more than 100,000 salmon.
After the cleanup, the dead fish were brought to a compost site in Tremont.