50,000 juvenile Atlantic salmon ranging from 200-400 grams have escaped from two net pen cages operated by Cooke Aquaculture in Machias Bay, Maine.

Salmon farm workers raised the alarm last week, as they discovered the loss of approximately 4.5% of the smolt stocked in pens at two Cooke Aquaculture sites located at Cross Island, Cutler.

Two pens showed signs of damage, which has been put down to predation by the local seal population.

“Divers inspected the nets to determine the seals point of entry. In accordance with farm management plans, the nets were confirmed to be properly tied, and that a second layer of predator netting was in place at both sites surrounding the primary netting,” the company said in a statement.

The company says it is investigating how the seals gained access to the cages. A Cooke spokesperson noted that the seal population has grown recently in Machias Bay, which seems to have led to “unusually aggressive seal behavior” as the animals compete for food.

The company added that the divers saw no fish near the cages, which it claims “suggests they were eaten by seals in the vicinity following the breach”.

In the wake of the salmon escapes, Cooke Aquaculture says it will assess the entire site to ensure that all predator nets are tied, and it will also increase the number of dives at each site, as well as “exploring enhanced netting options and safety measures on all remaining cages”.

The breach and the company’s corrective actions have been reported to the State of Maine authorities, in compliance with state regulations, Cooke confirmed.