Cooke Aquaculture, which runs two sites nearby, acknowledged two escape events in late August.
International conservation organisation The Atlantic Salmon Federation (ASF) has reported the discovery of 46 farmed salmon in the Magaguadavic River since Aug. 1.
The ASF is warning that farmed fish could endanger wild Atlantic salmon in the Bay of Fundy and the Gulf of Maine, reported local newspaper BDN on Wednesday.
Cooke Aquaculture, which runs two sites nearby, acknowledged two escape events in late August caused by seal-damaged nets.
More than one million smolt were being help at the sites, at Cross Island, Machias Bay. It is thought that 50,000 of these escaped through two holes before they were spotted by divers.
“Divers noted that there were no fish around the cages, which suggests they were eaten by seals in the vicinity following the breach,” the company said in a statement at the time.
The Maine Department of Marine Resources (DMR) witnessed as many as 100 seals on a half-tide haul-out near the lease site. Following the escape, divers inspected the nets to determine how the seals got into the cages.
In accordance with farm management plans, the nets were confirmed to be properly tied, with a second layer of predator netting in place around the primary netting.
“Based on Cooke’s report and our independent review of the gear, we consider this an isolated and unusual incident, and we are confident that Cooke has established a suitable corrective plan,” concluded DMR officials following the incident.
With the spawning season imminent, there are concerns that cross breeding could dilute wild strains.
ASF researchers have been finding the fish from as early as Aug. 1, before the reported breaches. The Cooke escapees were reported to be in 200-400g range, leaving the origin of these larger fish a mystery.
The organisation has identified most of the captured fish as females, some loaded with eggs, and weighing between 2 to 22 pounds. Mowi, the region’s other major salmon aquaculture company, has reported no similar incidents.
Since 2012, ASF has documented 386 escaped aquaculture salmon and only 33 native Atlantic salmon in the Magaguadavic. The breeding of commercial salmon, sometimes with European strains, creates significant genetic disparities with wild Atlantic salmon.
Canadian law prohibits the introduction and release of non-native fish, primarily because they can breed with native species, resulting in weaker progeny and further decline of wild Atlantic salmon stocks.