Pollution and wild salmon

Sir, – Fintan O’Toole has explained the dangers facing our stock of wild salmon (“We’ve ruthlessly driven salmon from our rivers”, Opinion & Analysis, April 30th). He points to the damage caused by pollution. One major source of pollution is the open-pen salmon farms operating off our coasts. The chemicals used to treat sea-lice, uneaten food and faeces drop to the sea bed, destroying all life there. They are particularly detrimental to juvenile fish.

Most countries have now banned open-pen farms. But Ireland still not only allows them to operate, but even subsidises them. – Yours, etc,

TIM McCORMICK,

Dublin 6.