Mass mortalities reported by Mowi (formerly Marine Harvest) because of algae blooms at two of their salmon farms in Bantry Bay are ‘partly caused the farms themselves’, according to local group Save Bantry Bay.

Algal blooms are becoming an increasing problem worldwide, with salmon farms in Chile reporting losses recently of 6,000 tons of fish. The recent death of 80,000 mature salmon at two of Mowi’s sites in Bantry Bay is said by the company to be as a result of a toxic algal bloom in late October. The true extent of the losses has not been fully established yet. The deaths have occurred only a few kilometres from the controversial proposed new mega-salmon farm site at Shot Head.

Blooms, which are monitored by the Department of Agriculture, Fisheries and Food, regularly force closure of the many mussel farms in the Bay, though the Department of Agriculture website does not show any algal blooms severe enough to stop mussel harvesting.

Overproduction of salmon in a confined area fuels the problem as their waste enriches the waters around the open cages. Cases of Sudden Death Syndrome have been reported previously in the company’s operations in Bantry Bay, a condition that which can trigger mass mortality in mature fish from even minor increases in stress.

According to the Company, the cause of death is a ‘naturally occurring toxic plankton bloom exacerbated by warmer waters which leads to the proliferation of various types of harmful plankton.”

However, Alex O’Donovan, Secretary of Save Bantry Bay, says the Company knows well that ‘There is nothing ‘natural’ about toxic algae blooms, which are caused by an increase in nutrients in the water from causes such as the discharges from the salmon farms themselves, which emits vast quantities of waste food and fish faeces directly into the waters.

‘The Company’s own Environmental Impact Statement makes it clear that that this is not a ‘natural’ phenomenon, stating: ‘The undesirable result of this is termed eutrophication, which is characterised by unnatural levels of plant growth (algae and phytoplankton in the aquatic environment).’ [EIS Vol. 1 p. 201]

‘The Company now has no choice but to face the fact that open cage salmon farming discharges all its waste into surrounding waters, enriching them. The Company’s own Environmental Impact Assessment records that the nutrient load on the Bay from the proposed Shot Head farm will be the equivalent of a town 4 times the size of Bantry for sewage phosphorus waste and 10 times the size of Bantry for sewage nitrogen waste. [EIS Vol. 1 p. 298]

‘At Shot Head the water circulates even more slowly than the outer bay where this mass fish kill has occurred. Slower circulating water means less dispersal of salmon farm waste, and more algal blooms.

‘Nor is the company’s attempt to shift the blame to global warming supported by any scientific research as scientific efforts to separate this from other causal factors are to date inconclusive. ‘

Kieran O’Shea, Chair of Save Bantry Bay said ‘It’s time for salmon farming to move to land-based tanks where all the inputs and outputs are controlled, just as our farmers must do on land. The technology is up and running in other countries and Ireland needs to follow to create a sustainable salmon farming industry which does not damage a Bay depending on fishing and tourism and previously known worldwide for its natural environment.’

The licence granted to the company for the 5,000-ton installation at Shot Head near Adrigole now faces three Judicial Reviews, including one from the State Agency Inland Fisheries Ireland. There are 14 Notice Parties to the Judicial Reviews, including Save Bantry Bay.

Two further Judicial Reviews are being brought by Salmon Watch Ireland and octogenarian environmental campaigner Peter Sweetman.



Chair, Save Bantry Bay, Kieran O’Shea, 086 1280303 (mobile) or 027 60121

Secretary, Save Bantry Bay, Alec O’Donovan, 087 7949227 (mobile) or 027 50508

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