Pike anglers are threatening to break the law in an attempt to stop the lawful netting of pike by commercial fishermen on Lough Erne.

They have mounted a campaign on Facebook in which they openly endorse sabotaging the fishermen's nets and equipment.

Despite an erroneous newspaper heading declaring "Illegal netting 'poses threat to angling tourism'" the netting is perfectly legal. The commercial fishermen are licensed by DCAL (Department of Culture, Arts and Leisure) to catch pike on the Erne during the open season from December 1, to February 28, each year. The fish are sold to dealers and exported to mainland Europe.

In fact the nets men are a key part of DCAL's management of Lough Erne. Pike prey on trout and hundreds of thousands of pounds have been spent at the Erne and Melvin Enhancement Company's hatchery at Florencecourt and an extensive restocking programme and river enhancement work to increase trout numbers. Without the nets men it might be necessary to cull pike to protect the trout.

As a spokesman explained: "The commercial fishery for pike in Lough Erne, particularly Lower Lough Erne, is in place to manage pike stocks to reduce their impact on trout stocks.

"This is in keeping with management practices elsewhere, including in high value large trout lakes in the West of Ireland, where pike numbers are deliberately kept at low levels by gill netting and removal, to prevent excessive predation on trout," he added.

Pike have been netted on Lough Erne for hundreds of years and today's fishermen are often carrying on a family tradition handed down from generation to generation.

According to DCAL the number of nets men is in decline. Only seven commercial fishermen took out a licence for the season that ended last week and of those seven only five took out a permit to actually go out and net pike.

A spokesman said the Department could restrict this number "should it be necessary" but the scientific evidence is that there are enough pike in the Erne to sustain the commercial fishery.

"The total commercial pike catch on the Erne in the 2011 season was just over 3,500," the spokesman added.

The fishermen have been quietly going about their business for decades but earlier this year Brian McCaffrey, a Sinn Fein member of Fermanagh District Council, expressed concern about the number of pike they were catching.

Anglers who had previously been oblivious to the fact that the pike were being netted were suddenly up in arms. Their anger was fuelled by a local man who posted a picture of a rope of buoys across the River Erne at the lock gates at Portora, just downstream of Enniskillen, asking "what chance does any fish have of getting through this maze of nets".

In fact there were no nets attached to the buoys. The buoys were there to warn people in boats that there were fyke nets in the area. Fyke nets are not nets in the traditional sense of the word but more closely resemble a series of interconnected lobster pots, designed to catch silver eels migrating to the sea to spawn. This is a "conservation fishery", aimed at saving the eels from being killed in the turbines of the hyrdro-electric dams at Belleek and Ballyshannon. The irony is that the only chance these endangered eels have of survival is to get caught in the fyke nets. They are then loaded into tanks and on to a lorry and transported by road around the dams before being released into the sea.

By design fyke nets rarely catch anything other than eels. Any pike that inadvertently ends up in the trap can simply be released.

However, several anglers reacted to the picture on Facebook by suggesting knives should be taken to the nets.

One wrote: "I would cut them nets into pieces and took my medicine from the cops." Another added: "they need cut loose".

The Enniskillen man who posted the picture suggested "they should be dragged on to the shore and burnt!" He later admitted to attempting "breakin n enterin" a green shed used by the fishermen.

"I tried it but it's far too noisy," he explained.

Neville Fickling, chairman of the Pike Anglers Club of Great Britain, condemned the idea of anglers taking illegal action to stop the commercial fishing.

He said he was aware of what anglers were trying to do in Northern Ireland and would encourage the government to cease the netting of pike on Lough Erne.

He said he had not seen the Facebook campaign but the Club's view was quite clear, that it wished to operate within the law.

"Direct action, anything like that, we would distance ourselves from that. We would actually disapprove of it," he said.

"The Club works within the law and seeks to change things within the law," he stressed.

A local representative of the Erne Pike Angling Association did not answer phone calls.

The Ulster Angling Federation, which represents trout anglers, did not respond to an email seeking its views on pike netting on the Erne.

DCAL did respond, stating that: "There is currently no scientific evidence to demonstrate that pike stocks are threatened by commercial operations.

"The enforcement of sanctuary areas and a legal minimum mesh size in the commercial fishery protects the breeding base of the pike stock," the spokesman explained.

"Effort and catch in the commercial pike fishery has reduced considerably over the past two decades," he added.

The spokesman explained that every three years scientists carry out test netting on the Erne to check the numbers of different species of fish in the lough. A survey is due to take place later this year.

"DCAL has commissioned further survey work specifically on pike stocks which will be completed in 2014. This will help inform any future management decisions," the spokesman stated.

He said DCAL believes there is a need for a more strategic approach to fisheries management on Lough Erne and is in the initial stages of developing a five-year plan.

"As part of this strategy, DCAL officials have already attended a number of meetings with stakeholders in the Fermanagh area to discuss a range of issues," explained the spokesman.

"DCAL will also review the arrangements for commercial pike fishing on the Lough, including the cost of licences, improvements to the catch data returns required from fishermen and compliance inspections," he added.