A ban on the use of aircraft to spread fertiliser on forestry plantations has been demanded in the North Western Regional Fishery Board region, which stretches from Clew Bay in Mayo to Mullaghmore Head in Sligo.
There has been increasing concern over water quality in the region's lake and water systems in recent years due to enrichment.
As well as the River Moy, which produces about 6,000 salmon on the rod annually, the region also boasts two quality wild brown trout lakes - Lough Conn and Lough Arrow.
The spreading of fertiliser, both from the air and by hand, to nourish an increasing acreage of commercial trees is suspected of being a major factor in the decline of water quality.
Now the North Western Regional Fishery Board, against a background of the closure of Carrowmore Lake in north Mayo to anglers for a second consecutive season, has taken a unanimous decision to demand that the Government impose a total ban on aerial fertilisation in their region.
"We cannot prove conclusively that what is happening on Carrowmore Lake is due to fertilisers used in forestry, but they are a prime suspect," board chairman Mr John Walkin said yesterday
He added that angling tourism has been devastated on Carrowmore Lake, near Bangor Erris, because of huge algae bloom.
"The loss of tourist revenue is unbelievable", Mr Walkin said. "This is a local disaster for the pub, restaurant and B&B sector".
A member of Mayo County Council, Mr Gerry Coyle (Erris) has welcomed the fishery board motion which was passed unanimously at a meeting last week.
But he said he felt the proposal should have gone further and also called for a ban on the spreading of fertiliser by hand.
Carrowmore Lake is the source of the drinking water supply for the entire Erris region. At an area meeting of county councillors in Belmullet last week, Mr Tim Quinn said it was important that the message to go from the meeting was that the water in the lake had been tested and was non-toxic and therefore safe to drink.