Anglers wish to double a array of fish-eating cormorants and goosanders they can fire in Wales.
The Angling Trust claims a birds are decimating salmon and sea fish stocks.
It wants Natural Resources Wales (NRW) to make it easier for anglers to request for licences to kill them.
The Welsh Ornithological Society pronounced there was not adequate justification a birds were a problem, while NRW pronounced it was not formulation to make any changes to a chartering system.
Since 2013, 80 licences have been issued, 130 goosanders have been shot and 347 cormorants have also been culled.
Applicants need to infer they have attempted to shock off a birds and benefaction a month’s value of counting information for a widen of river.
Cormorant numbers started to arise after it became a stable class in 1981 and anglers explain goosanders – a “saw-billed” steep – are now a common steer on many Welsh rivers too.
Each bird can eat adult to a bruise of fish a day.
In new years, a debate by a Angling Trust in England has led to a examination by a UK supervision of a array of birds that are authorised to be shot and a introduction of a simplified looseness focus form.
The gift now wants to see movement in Wales.
Angling is suspicion to minister about £150m a year to a Welsh economy, with rivers eminent for their salmon and sea-trout, famous locally as sewin.
But progressing this year, NRW reported fish bonds had strike “unprecedented lows”.
It due new bylaws, including creation it imperative for anglers to chuck behind a fish they locate for a subsequent 10 years.
Mark Lloyd, arch executive of a Angling Trust, pronounced it would now be “timely to concede anglers larger leisure to control cormorants and goosanders”.
He claimed a stream array of licences being released to fire a birds would make “no hole during all in a population”.
“We would like there to be a doubling of those numbers and to make it most reduction formidable for fishermen to request for licences,” he added.
The gift has launched a website where people can record when they mark a birds fishing inland.
But a Welsh Ornithological Society pronounced “a array of pointless sightings” would not yield sufficient justification for some-more licences to be granted.
Chairman Mick Green pronounced grave and systematic stream surveys would be needed.
“We consider there needs to be correct systematic surveys finished to settle what a race of these birds indeed is and what a turn of stream use is, before any licences are given,” he said.
“It’s usually afterwards that we can be certain there won’t be any inauspicious outcome on a race of these stable species.”
He combined H2O peculiarity and medium decrease could minister to fish decrease and some-more should be finished to tackle those issues “rather than blaming wildlife”.
Nick Thomas, NRW’s north easterly Wales operations manager, pronounced it realised fish-eating birds could be carrying an impact though it indispensable justification of specific mistreat before giving accede to fire a birds.
“Provided fishermen supply us with information we are prepared to emanate licences,” he added.