Storms hit fish farm company’s ability to treat disease

A Norwegian company seeking to expand its fish farming operation in West Cork has admitted that severe storms compromised its ability to treat its salmon for sea lice and other diseases last year — prompting environmentalists to say this bolsters their argument for closed containment systems.

Marine Harvest Ireland, producer of 80% of Irish farmed salmon, said the storms also affected its ability to treat fish with amoebic gill disease (AGD), a parasite that usually causes fish to stop eating, where mortalities are common.

Friends of the Irish Environment (FIE) said Marine Harvest’s difficulties treating sea lice and AGD was “further evidence that along our coastal bays closed containment systems, which are now coming into production around the world, are the only way forward”. Closed systems separate farmed fish from wild fish and the environment, containing the fish and water within the farm. Supporters of closed systems argue that waste, escapes, and spread of disease and parasites are much better controlled in these systems.