As Galway Bay FM reports, campaigners Galway Bay Against Salmon Cages - one of the groups opposed to the planned Galway Bay fish farm - say that cypermethrin, an active ingredient in veterinary medicine used to treat sea lice, is toxic to aquatic organisms.
BIM aquaculture manager Donal Maguire attempted to play down fears over the use of the pesticide, saying it has been fully tested for toxicology in the marine environment.
However, another campaign group claims BIM's position is contrary to the manufacturer's own warnings on the use of the drug.
According to FishNews.eu, Friends of the Irish Environment (FIE) cited the Irish Medicines Board's product description for cypermethrin, which states that it is "dangerous to fish and other aquatic life" and demands that the chemical "should not be allowed to contaminate water".
FIE went on to describe cypermethrin as "a biocide which kills life, not a medicine that saves lives" and as "a highly active neurotoxin" with "known effects on fish and, most sensitive of all, crustaceans such as crabs and lobsters. Bathers and watersports [enthusiasts] may also be at risk."
Earlier this month, Inland Fisheries Ireland (IFI) expressed "serious concerns" over the findings of a study on wild salmon in Ireland that claimed fish farm schemes were less harmful to wild fish than pollution and possibly even beneficial to wild catchments.
IFI is among the significant opposition to BIM's proposed organic salmon farm off the Aran Islands, a 500-hectare project that would be the largest of its kind in Europe and create hundreds of jobs in the locality.