The Sunday Herald’s investigation has revealed that the fish farm chemical Emamectin Benzoate (EMB) has polluted Scottish lochs in breach of environmental safety limits (Toxic pesticide ban is scrapped after fish farm industry pressure, News, March 19).

Yet the Scottish Environment Protection Agency (Sepa) seems to have changed its mind about banning Emamectin and is reviewing its existing licences instead. Emamectin is concerning where new fish farms are proposed, such as at Dounie on the Sound of Jura.

The shellfish at Dounie are economically valuable, caught by creel fishermen and destined to be eaten by people, and by the critically endangered skate living in the Marine Protected Area (MPA) where the fish farm is proposed. SNH have expressed concern about this to Sepa.

Sepa's has two functions, beside supporting economic growth: to protect the environment and human health, and ensure Scotland?s natural resources are used sustainably. We call on Sepa to exercise the precautionary principle and grant no licences for new fish farms within MPAs or other protected areas, such as the farm at Dounie, until they can be certain the use of sea lice chemicals isn't harming marine wildlife.

John Aitchison and Mark Smith

Friends of the Sound of Jura

Tayvallich, Argyll