A warning has been issued of a "looming" crisis on a Scottish loch due to the advance of a major predator.
American signal crayfish, which can eat young fish and destroy their habitat, have been found in increasing numbers at Loch Ken in Dumfries and Galloway.
Bob Williams of the Glenkens Business Association said the problem was having a "major impact" on trade in the area.
Local councillor Peter Duncan said it was time for action before the situation deteriorated any further.
Hoteliers in the area say they have seen a significant downturn in the number of fishermen coming to the loch.
They say many of them are abandoning south west Scotland for the more consistent fishing in Holland and Ireland.
A loss of a group weekend booking can cost them between £3,000 and £4,000.
Dave Paterson of the Kenbridge Hotel said it affected more than the hospitality industry.
"Loch Ken has been a Mecca for fishermen for many years," he said.
"If the standards are dropping then we are going to have less people coming here.
"This impacts obviously on the hotels but it also impacts on the businesses and the infrastructure of the area."
Cliff Winstanley, who has fished the loch for many years, agreed that the problem was getting worse.
"In the last 10 years the crayfish have multiplied and multiplied every year," he said.
"It is literally unfishable at times on Loch Ken in the summer.
"I'm seeing a decline of the trout and salmon and other species."
He believes the situation is so serious that the only solution is either to trap the crayfish for eating or to cull them.
"You can put a dead bait on and pull seven or eight crayfish out at one time - it's as bad as that on the loch," he said.
Business association leader Mr Williams said the fishing problems were being felt right across the area.
"It is a major concern to the vast majority of the members of the business association," he said.
"Almost all of us are involved in some way or another with the tourist trade.
"Once fishermen find other waters they will never return, so this needs to be nipped in the bud now."
Local councillor Mr Duncan has also called for action.
"There is clearly a crisis looming," he said.
"Fishing is such a big part of the local economy and action needs to be forthcoming now.
"If this was an impending factory closure in the central belt of Scotland there would be a complete joint action to resolve the situation."