Salmon trapped in poachers' nets are dying in the heat, an Irish cross-border agency has warned.
Poachers often target salmon in the Foyle river system, which runs through counties Donegal, Tyrone and Londonderry.
If fisheries officers find a net they usually cut the fish free and release them back into the river.
But the Loughs Agency said hundreds more fish than usual are dying from the heat before they can be released.
John McCartney, the director of conservation at the Loughs Agency, said over 40 fish were found on Thursday.
"Normally, if you have five or six fish in the net you might get one that dies but the other four or five would be released," he said.
"Unfortunately, with the high temperatures the fish are so stressed that when they get caught in these poaching nets they're dying within minutes."
'Frustrating' Mr McCartney said at this time of year he would normally be disappointed to see even one or two fish die in the nets.
"I would expect the staff to cut them out to release them," he said. More....