IT HAS been described as the freshwater equivalent of the great white shark: a ferocious predator that can weigh more than 50lbs, armed with rows of razor-sharp teeth, and which devours its own.
Now evidence is growing that thrill-seeking anglers are deliberately introducing the fearsome pike to some of Scotland’s most prized trout and salmon waters.
Wildlife groups say the voracious fish threatens to wipe out native species in some of the country’s most celebrated lochs and rivers.
Pike fishing is a sport which attracts growing numbers of anglers, who pursue their quarry with a grim determination and will travel hundreds of miles to catch a record-sized fish.
The World Wide Fund for Nature (WWF) Scotland claims there is hard evidence that anglers are deliberately releasing adult pike into Scottish waterways purely for sport, even though they are not native to northern waters.
The fear of the WWF and other groups is that pike will devastate native brown trout stocks and pose a danger to already dwindling numbers of char, a game fish of the salmon-trout family.
The information has been provided to the WWF by the Spey River Board and local anglers. Loch Ness is another famous waterway into which pike have been introduced for sporting purposes.
Mike Donaghy, of WWF Scotland, said: "We have a group of selfish and irresponsible pike anglers who see it as their duty to move pike around and populate more rivers and lochs to suit themselves.
"My main concern is that they will feast on brown trout and char. But worse than that, there are many lochs where there are no fish and they have a rather unique ecosystem where the top predator is a newt, and if pike end up in there they will eat everything and it will be a complete ecological disaster."
Rogue anglers are also alleged to have released pike bait - including perch, rudd, roach and carp - into waterways where they may not previously have existed, posing a disease risk to native species.
Donaghy said: "Pike are ferocious and very hungry. They continue feeding way past being full - they just keep eating. Females are often found stuffed-full because they are highly opportunistic and lay even more eggs the bigger they are. So you could go and catch a load of pike, but if you miss a few big females then they are there to stay."
The Pike Anglers Club of Great Britain claims the fish has existed in Scottish waters for at least 10,000 years.
This is contested by many Scottish experts who believe the pike found in Highland rivers and lochs are only there because they were artificially introduced.
One of Scotland’s top fish biology experts, Ron Greer, believes that pike is not native to the Highlands.
He said: "Moving a pike to the Highlands is like moving rats to the South Seas. We worry about grey squirrels replacing the red squirrel but we should regard pike in the Highlands as an underwater grey squirrel or underwater mink.
"This clandestine movement of pike to new unnatural environments is causing a terrible effect. The responsible pike anglers don’t do that, but they are not the danger. As usual, it is an irresponsible small band of misfits that are providing these dangers."
Greer’s views were echoed by leading fishing writer and journalist Bruce Sandison. He said: "I have no knowledge of any indigenous species of pike in our northern lochs, but they have definitely spread. There are now pike to be found in Loch Garry, Loch Loyne and waters in Wester Ross - all placed there by anglers.
"It would concern me greatly if anybody maliciously introduced pike into these waters, because it does irreparable damage to the natural environment.
"There is no law in Scotland that prevents people from introducing other species, although there is in England and Wales. That seems to me to be very remiss on the part of the Scottish Executive not to address this issue."
Andrew Wallace, director of the Association of Salmon Fisheries Board, admitted that coarse angling was "extremely important" to Scotland’s economy as it generates around 130m every year.
However, he added: "It is essential that at some point in the future some form of control or regulation of these transfers is brought into effect."
Last night, Robert Murray, general secretary of the Pike Anglers Club of Great Britain, said: "We condemn 100% any angler who illegally introduces a new species of fish to a water and interferes with a balanced environment."
But he said predators were "essential" to a balanced natural environment and to help maintain a healthy stock of prey fish by removing the old, weak and diseased fish from the water.
"The best controller of the pike population in a water is the pike itself - large pike eat lots of small pike, maintaining a balanced predator population that is not overrun with small jack pike," he added.
A Scottish Executive spokesman said they would be looking at the transfer of species between waterways as part of a review of freshwater fishing.
PIKE can live for up to 50 years. The markings on adult pike are as individual as fingerprints and hardly change during their lifespan, enabling anglers and researchers to identify individual fish.
Most pike heavier than 10lb are female, with male pike larger than 12lb being rare. The female pike can produce around 200,000 eggs.
Females carry eggs for most of the year, with egg development beginning in the summer following the springtime spawn. In winter and spring the eggs mature and swell by absorbing water.
Pike tend to live on a diet of
whatever fish is available in their waters, such as perch, salmon and trout.
According to the Pike Anglers’ Club of Great Britain, the largest pike caught on rod and line in Scotland weighed in at 47lb 11oz.
The fish was caught by Tommy Morgan on Loch Lomond in 1945.