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.
Tony Lowe, FIE spokesman, said closed systems meant “disease and parasites can be controlled without adverse effects on other species and the effluent recycled rather than polluting local waters”.
In its report for the final quarter of 2013, Marine Harvest, which operates worldwide but has its Irish HQ in Donegal, said it was “operationally... very challenging for the Irish unit”. As well as the difficulties treating sea lice and AGD, two Irish sites, not identified in the report, were severely affected by pancreas disease, a viral infection that leads to increased mortality, weight loss and low, fish-product quality. As a result, Marine Harvest took the decision to halt fish harvesting in Ireland from the start of the year up to February 17 next “in an effort to grow the fish”.
Weather permitting, it was the company’s intention to go back to harvesting by February 17, the company’s technical manager Catherine McManus said.