Campaigners have criticised the UK cull of up to 3,000 cormorants to keep them off fishing lakes and rivers.
Cormorants have been moving inland in recent years
The government has issued licences to kill the birds between now and April.
The Royal Society for the Protection of Birds claims the rules on shooting have been relaxed in response to pressure from angling groups.
But the National Federation of Anglers (NFA) said what was planned was a range of measures, including bird-scaring and fish shelters, not a wholesale cull.
Cormorants have been moving inland in recent years and eating the fish from lakes, rivers and canals, said the BBC's environment correspondent Tim Hirsch.
Most anglers regard them as unwelcome competition and want the right to shoot the birds to keep their numbers down, he explained.
He added that last year only 1,200 out of a maximum of 3,000 were reported to have been shot.
A spokesman for the RSPB said it was natural that cormorants would take fish from "put and take" commercial fishing ponds.
"Fish and cormorants have evolved together for millennia - if you put in a fish refuge, the fish can hide and the problem can be reduced.
"If the full quota of birds were killed in England per annum the overall population would be reduced. That is not the stated aim of the government."
The RSPB's Andre Farrar said the organisation had always supported licences to kill some birds "in limited circumstances".
But he said the liberalisation of rules on licences had been "given on a plate" by the government.
The NFA said: "The RSPB seems to be suggesting that anglers want to exterminate the cormorant population, but this is not the case.
"Most anglers simply want the fish stocks in their local waters protected from devastating cormorant feeding.
"Shooting is only one tool that is being used to protect fish stocks. Many clubs and fisheries are investigating a wide range of methods to combat the problem of cormorants besides shooting.
Methods such as bird scarers (mechanical or human) and fish refuges all had their part, the NFA said.
"Fish stocking policies whereby larger fish are stocked can also help in reducing the amount of smaller fish available for the cormorants to feed on."
Labour MP Martin Salter, parliamentary spokesman for angling and shooting, said the cormorant population (some 23,000 overwintering in Great Britain) had increased by 70% since 1989 and threatened freshwater species including eels, brown trout, salmon, dace and roach.
He accused the RSPB of scaremongering and said the cormorants ate so many fish they threatened other bird predators such as herons.