Scotland on Sunday – Sport – Other Sport – Rise in American crayfish is bad signal for Scottish rivers

Scotland on Sunday – Sport – Other Sport – Rise in American crayfish is bad signal for Scottish rivers

THE American signal crayfish has been grabbing headlines again after being found in the River Ettrick, a main tributary of the Tweed.

Unfortunately, the threat of this invasive species is nothing new. It was introduced into England in the mid-1970s to farm for the table and has since established itself in the wild on many southern rivers, where it has wiped out the smaller native white-clawed crayfish.

In Scotland we have no indigenous crayfish but signal crayfish, which grow to over 20cm, are omnivores and can prey on small fish and fish eggs. They also reach high densities per square metre and can bury hard, leading to unstable riverbanks and damage to salmon and trout spawning grounds.

At the start of this year it emerged that colonies were present in the Dee in Kirkudbrightshire and the River Clyde and, indeed, that work had been ongoing for almost five years by the United Clyde Angling Protective Association to try and eradicate them from a section of the Lanarkshire water.

The fact they have now found their way into as rich a salmon spawning area of the Tweed system as the Ettrick is obviously very bad news.

I personally have not came up against these critters but I believe they are being introduced so that people can sell them. I was reading another article in the Herald the other day that was saying the the bailifs on Loch Lomond were stopping people from trying to stock Barbel into the Loch.
Barbel into Loch Lomond

Loch Lomond: Anglers treading a dangerous line

FISHERMEN have been caught deliberately trying to introduce foreign species of fish into Loch Lomond, despite repeated warnings of the damage they do to rare native species.
Water bailiffs around the loch have twice caught fishermen with containers of live barbel, which can grow up to 20lb and which feed on eggs of other fish.


  1. Pingback: Urban Flyfishing on the Kelvin » Thats interesting!!
  2. zaelic · December 13, 2004

    Eat the little buggers! They are good, and they tend to breed and frow slowlky in cold waters, so it is pretty easy to eat out a population. I accidentally caused a ecological disaster in the Macedonian Republic some years back when I showed my local friends how to catch and prepare crawfish from the local mountain stream. Once the villagers realized that you could eat these things in spicy soup, they pretty much cleared out the ecosystem in two years. But you are talking about non-native invasive appetizers here, right?

  3. Alistair · December 13, 2004

    It would be nice if you came over here and ate all our buggers 🙂

  4. Rob · December 13, 2004

    Quote “Water bailiffs around the loch have twice caught fishermen with containers of live barbel, which can grow up to 20lb and which feed on eggs of other fish.”

    Utter rubbish. Any coarse angler worth there salt knows that Barbel are fast water fish. It would be extremely unlikely that (a) they would survive in the loch, (b) that they would spawn and (c) they would eat other fishes eggs, although this cannot be ruled out as ALL fish, especially Brown Trout, will scoff eggs if they are hungry enough.
    Also, the British record has only just gone over 20 pounds in the last few months, and this was an exceptionale fish. The Scottish record stands officially at 8 lb..bit of a difference there. What has probably happened is baliffs have caught people with Gudgeon, a fish sometimes used as live bait for Pike. These fish grow to 6oz or so but look like baby barbel. B

  5. Rob · December 13, 2004

    Ahhh. I thought so…it was NOT loch Lomond, it was the River Clyde!!! Bit of a difference. Barbel have been there since 1967 by the way. Here is the storry in full.

    Barbel pose threat to Scottish rivers
    Barbel are breeding in the River Clyde, Scotland, threatening the ecosystem that supports a salmon fishery, according to a story in today’s Herald.

    Barbel (Barbus barbus) are large, omnivorous cyprinids and can reach over 20lb in weight. It is thought that the barbel have been deliberately introduced into the Clyde by anglers, as they are a prized sport fish.

    Professor Peter Maitland of the Fish Conservation Centre told The Herald: “It will be easy now for Barbel to be transferred to other rivers in Scotland. The main concern over these fish in the Clyde is that they grow very big, and as bottom feeders, it is likely that they will feed on eggs in the gravel.

    “There is also every likelihood that they are competing for space with native species.”
    More at: The Herald (December 26, 2003)

  6. bailiffs · December 13, 2004

    You can get some good fishing out of Loch Lomand. There’s Salmon on Loch Lomond and the River Leven. Pike on Loch Lomond from the boat or the bank. Coarse fishing on the River Endrick and on Loch Lomond. Also rainbow trout fishing at local fisheries.

  7. john mccahon · December 13, 2004

    can any one tell me where to catch the cray fish just bought net for them thought i would give it a try plz emaill me at i stay near strathclyde park thanks

  8. Alistair · December 13, 2004

    Hello there,

    Got this from another site!
    Because the traps and fyke nets commonly used to catch crayfish are “Fixed Engines” as defined by the Salmon and Freshwater Fisheries Act (1975); unless authorised by byelaws, the use of these instruments to catch crayfish is an offence under Section 6 of SAFFA (1975). Therefore, while fishing for crayfish is legal, unless crayfish traps are authorised by byelaws, their use is illegal, even where they are used within a site registered as a fish farm.

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