One of the most voracious and destructive alien species to invade our shores in recent times has now reached the point where it is virtually impossible to eradicate, Angling Times can reveal.
Since arriving in this country in the late- 1970s , American signal crayfish have slowly crawled their way into every corner of the UK’s canal and river systems, plaguing fish stocks and anglers everywhere.
And while conservationists have focused on the plight of our native white-clawed crays being wiped out by a fungal plague carried by the signals, angling’s case has largely been ignored. But the fact is that once a fishery has been infested it becomes virtually impossible to fish as the crays seize legered baits almost as soon as they hit the deck and even swim up in the water to take float fished offerings.
Worryingly for anglers, it appears that the scientific consensus seems to be that crays are here to stay and very little, if anything, can be done to halt their relentless progress.
“There has never been a case anywhere in the world of an alien species being eradicated once it has become established. I suspect that, when it comes to signal crays, we’re stuck with them,” said Environment Agency policy manager Heidi Stone.
“On the subject of trying to manage them, we have only three options – do nothing, trap them occasionally, or continuously and aggressively trap and remove them,” she said.
Doing nothing seems to be the present policy which, as it turns out, is better than doing the wrong thing which tends to be just removing a few.
“Occasional removals just reduce the numbers of adult crayfish which are cannibalistic. This, in turn, merely leads to a boom in the numbers of young crays. “Aggressive trapping is very expensive, never removes all the crays and, once stopped, the numbers soon bounce back. There have also been issues with otters and water voles drowning in traps over the past two years,” she added.
Scottish environment minister Mike Russell last week encouraged anglers north of the border to ‘kill signal crays on sight’ following the revelation that the species has spread rapidly since first appearing in the River Dee in 1995. The policy cannot be adopted in England for fear that anglers would end up killing the endangered native white- clawed crays by mistake.
“Many anglers have still to learn just how much of a problem these things are. On the rivers I fish they have learnt to attack the boilie stop to get your baits off the hair and even floatfishing is impossible because they’ll take a bait fished a foot off the bottom. No angler’s bait is safe,” insisted Oxford-based Geoffrey Butler, of tackle giant Drennan International.
“If crays were non-native predatory birds f lying into people’s gardens, eating songbirds and destroying the habitat, there would be public uproar and something would have been done about it.
“But because it’s fishing and ‘out of sight’ so to speak, it seems this decimation is ok. They’re destroying the fishing for everyone around here and something must be done before the situation is beyond repair,” he added.