Crayfish imbalance

[sawire]

Do you consider it damaging to take american signal crayfish from a river infested with them? Does this unbalance the natural predation cycle of these cannabalistic scavengers? I have read that the lack of the larger animals encourages the spread of the smaller ones thereby causing more damage. I am not convinced by this argument. What are your thoughts?

[Red Robin]

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I think it's all a matter of degree of infestation. The term "infestation" does imply an excessive and imbalanced amount and therefore potentially a problem or two or three.

I don't buy into the 'only allow native species' school of thought. Afterall, nearly everything was 'alien' once upon a time (including people) and changes and migrations are all a valid part of evolution.

Nature usually finds a way and balances itself over time but mankind wants to play god and has dreamed up lots of rules.

I don't know enough about this species of crayfish to comment any further.

[Ukwildlifeo]

Originally Posted by Red Robin

I don't buy into the 'only allow native species' school of thought. Afterall, nearly everything was 'alien' once upon a time (including people) and changes and migrations are all a valid part of evolution.

There is nothing natural about an American species in Europe, especially one as destructive as the Signal crayfish. And its certainly not evolution!

On the subject of the original post, Ive not heard this in Crayfish, but I have heard about something similar in territorial animals, where when a dominant large individual is removed a number of smaller ones will take its place. But Im not sure if signal crayfish are territorial or whether a few smaller indiviaduals would do more damage than one large individual.

[caernerch]

efforts are being made on some rivers to remove them. one thing in my book tips the balance of the argument. they're delicious.
regards
caernerch

[Red Robin]

Originally Posted by Ukwildlifeo

There is nothing natural about an American species in Europe, especially one as destructive as the Signal crayfish. And its certainly not evolution!

....By use of the word "natural" I mean without interference from mankind.

By use of the word "evolution" I mean changing over a period of time and, in this context, not biological/physiological changes such as dynosaurs growing into birds or whatever.

Fair enough if you think differently - We can agree to differ.

So, these yankee crayfish have arrived here just like cats and rats etc and as they are reported to be tasty to eat, will have their own predators and a different balance will evolve. There may be casualties on the way - There invariably are, such is wildlife - It's no big deal unless you are against change in any form.

Isn't this the definition of life which is wild?

[Red Robin]

Originally Posted by caernerch

efforts are being made on some rivers to remove them. one thing in my book tips the balance of the argument. they're delicious.
regards
caernerch

....Tell us more! Have you eaten them? Are they easy to catch? How big are they? Recipes?

Yum-yum, pig's bum, bring it on!

Hmm, I'm wondering how they are being removed? Not by man-made substances I hope. By the introduction of Whales? I expect Otters will like them.

[caernerch]

you can get a crayfish trap for about £5 on ebay. bait it with anything organic - the smellier the better. chuck it in and leave overnight. they can be cooked like prawns. serve with marie' rose or nantua sauce.

CAUTION: familiarize yourself with the native species and put them back where you found them along with any other native wildlife.
regards
caernerch

PS they're what the Beverly Hillbillies call "crawdabs".

[Delf]

Get a licience to trap, if they will not issue you one its because there are still our highly endangered native cray in your area. The native white clawed is truly on the brink of extinction...you people here are supposed to be nature lovers.

If your going to trap crayfish at least be sure you are not causing more problems, get a licience and make sure you can tell the difference between the two, it can be tricky with smaller cray.

Crayfish trapping advice packs are available from the National Fisheries Laboratory. Or contact the Fish Movements Authorisation Team on 01480 483968.

Dont hold your breath on getting permission, and please dont follow advice on crayfish trapping from a cooking tv show. Cooks dont give a xexexexe for nature. If you see people using traps ask to see their licience if they refuse to show it phone the fisheries bailiff.

[Red Robin]

Originally Posted by caernerch

CAUTION: familiarize yourself with the native species and put them back where you found them along with any other native wildlife.

....Thanks for the trap 'n cook advice, caernerch

Anybody got some photos of both native and foreign crayfish so we can tell the difference, please?

[Red Robin]

Originally Posted by Delf

Get a licience to trap, if they will not issue you one its because there are still our highly endangered native cray in your area. The native white clawed is truly on the brink of extinction...you people here are supposed to be nature lovers.

If your going to trap crayfish at least be sure you are not causing more problems, get a licience and make sure you can tell the difference between the two, it can be tricky with smaller cray.

Crayfish trapping advice packs are available from the National Fisheries Laboratory. Or contact the Fish Movements Authorisation Team on 01480 483968.

....Excellent advice

So, how have the native white clawed variety come to be highly endangered?