Signal Crayfish ?

[Jeff Woodhouse]

I believe one or possibly more of the Scandanavian countries had some success by trapping crays,neutering the big males

Quite easy using the castrating camel method of two bricks. Easy to make a mistake though and squash the poor little critter, but a few million attempts should get it right.


You can trap them BUT the trap has to conform to certain sizes, mainly to stop otters and voles getting in, and they MUST be registered when you apply for a licence. Costs nothing though and you get a tag to put on all your traps.

The EA are testing a powder to kill off the zebra mussels, but I hope it doesn't harm the native swan mussels.

EDIT bit : you can also try getting a tin of cat food and tying some string around it long enough to throw in the water and tie it to the bank. Punch holes around the tin for the flavours leach out, that attracts them whilst you get on with fishing. Mind you, all the fish will be around the tin as well.

 

[S-Kippy]

We've had them in my local canal for many years, and lots of them. What's surprised me is that the fish population has barely changed in that time, if it all. OK they are a nuisance, but other than that, is there any proof that they, on their own, have destroyed fisheries?

Cormorants though, are a different matter. They have virtually wiped out the population of Grayling from the Mersey basin, in just one cold winter.

Proof ? Depends what you mean by proof. I'm not sure certain interested parties even accept there is a cormorant problem yet we know there is. These things are thriving & spreading so they must be eating something as well as anglers baits such as the native crayfish,invertebrates and fish spawn/fry all of which to me is pretty compelling. Add to that the fact that the small/silver fish populations of many rivers [not all] are in serious decline. I dont think you can pin it all on signals or all on cormorants but they [plus environmental factors] are the main causes. When they are not eating fish or fish spawn they're eating the stuff fish feed on...and the decline of fish stocks is hastened.They have reached plague levels in many rivers and are now colonising stillwaters too. When did native crayfish ever do that ? These things do not happily co-exist...they are like locusts or the Borg.

Without some form of intervention/control I think the future is bleak.I can't see their advance being stopped & population levels will level out or drop only when there is nothing left for them to eat but themselves. These are not shy,retiring,quirky parts of our natural fauna...signal crays are an aggresive & invasive alien species which are not being controlled naturally because we dont have enough natural predators in our rivers to do the job and we haven't come up with a viable means of controlling them yet....if the will to do so is even there let alone the funds.

I'm on one now. I hate these damned things because of what they are doing to our rivers but most of all because they've driven me off the river I love that I'd fished since I was a kid and will probably now never fish again.

And yes...it really is that bad as anyone who has fished a river full of these things will confirm.They can reportedly live for 20 years and reach 18 cm in length.

 

[Ric Elwin]

Yes of course crayfish have to eat something. When they first appeared in my area, I feared for the future. I expected them to clear up most of the spawn each year leaving us with just a small number of large fish. On waters where cormorants are present in large number e.g. the Mersey, this is exactly the situation we have today.. But on the Macclesfield Canal, where I've never seen a cormorant, fish stocks seem unaffected. If anything, there are more fish of all sizes today than there were 10 years ago, when crayfish first appeared here.

I don't know what crayfish eat. I would guess the answer is almost anything. It must include fish spawn, and maybe small fish. But are they clearing up here, to the extent that there are few fish coming through to replace those that die? On their own, without other negative factors? I'm not sure..

I know my evidence is only local, it could be different elsewhere. But evidence it is, suggesting that cormorants are guilty of denuding stocks of fish up to around 2lb. Crays on the other hand, are guilty of being a massive nuisance to angling with most established methods.

 

[Simon K]

I've fished the Lea for 10 years now and, although they've always been there, they've never been so bad as now. Largely I think this is due to the lack of mature fish (barbel, chub, perch) the former two species decimated in a fish-kill about 4-5 years ago. Where there were always some fish in or around most swims to keep the crays at bay, now the only time you don't suffer their attentions is when a fish moves in.

It's real nightmare.

Bio-engineering some kind of virus/bacterial agent most likely won't work as there will inevitably be a few that survive it and go on to produce an immune population.

The only way I can see is to keep stock levels up to scratch as much as possible and thus keep their numbers under control. I really don't think we'll ever be rid of them.

Raising EA sourced species to maturer sizes (logically, in protected stillwaters) before stocking rivers seems to me to be the most cost-efficient and sensible way forward. The other advantage is that bigger fish would be more cormorant-proof too.

Until winter sets in and their activity backs off, the only way is to fish artificial baits or just fish through them until your target species turns up.

 

[Fred Bonney]

just has a look on the EA website. Turns out to be an offence, should you catch one whilst fishing, to return it alive. Since I am not in the habit of carrying a brick with me i don't really know how to deal with them. Anyone out there got a method of dealing with the b******d's?

I used to take a plastic bag with me on the Upper Ouse and put them in that, and take them home for the pot. Make sure the bag is tied shut though, they will find a way out!
Alternatively a bank stick stabbed behind the head does the trick, but don't put them back it's illegal.

 

[uscarper]

crayfish will eat about anything, including each other. plants. fish eggs, dead fish, live fish if there small enough to catch. when they molt their shell they are basically sitting ducks as they cannot move until the new shell hardens, other craws will attack it and eat it then. they are tasty as no-knot says. we can use for bait here but are expensive at about a dollar a peice for soft ones. carp go nuts for them here as do catfish. i wonder if they could be trapped and used to make pellets and or boilies?

 

[S-Kippy]

Trapping them would barely scratch the surface....and I suspect merely create a temporary respite that would quickly be filled.Simon's experiences on the Lea is what I think we can all look forward too. Unless there are enough year classes of smaller fish coming through to replace the current stocks of big fish the situation is only going to get worse....and there aren't because the signals & cormorants between them are seeing to that. We already have many rivers that contain a reducing population of very big fish and not much else....once these are gone the rivers will crash.

I dont think we'll ever be rid of them either...nor do I think we'll ever get them under any sort of effective control because they breed like flies.

I admire people who can fish through these things.I cant.

 

[Bob Hornegold]

A mate of mine who fishes a Private section of the Lea has a licence to trap Crays and in the first week he trapped 5000 of the critters !!

He reckons he has only scratched the surface and there is such a glut of Crays, he can't give them away ?

It's completely mad, if you combine the Crays to the Cormerants breeding on the islands of Landridge and the Otters running wild in the Lea Valley, no wonder fishing is difficult ?

Bob

 

[barbelboi]

That’s terrible Bob, thankfully I have never encountered them on the stretches of the Colne and Loddon that I frequent YET. As tributaries of the Thames I suppose it’s only a matter of time.
Jerry

 

[noknot]

5000, that's got to worth some $$$$$$ to somebody???
It's OK using plastic baits, but they can move and tangle up your rigs too!

 

[chav professor]

What do crays eat (bait wise) - I have experience of them eating lobworms and luncheon meat. Do they attack bread flake, cheese paste, maggots with similar gusto? can they be avoided by presenting a bait float fished??

Stocking the Lea with fish looks like it could be the only viable solution - very worrying.......

Do crays proliferate to the same extent on all rivers? Or are some more susceptable than others???

 

[beerweasel]

I'm surprised there is not a market for them, after all they are freshwater scampi.
I would have thought the chinese takeaways would have them, I'm sure where Noknot is they would (they eat everything else). :w

 

[noknot]

I'm surprised there is not a market for them, after all they are freshwater scampi.
I would have thought the chinese takeaways would have them, I'm sure where Noknot is they would (they eat everything else). :w

Indeed Mr Beerweasel! I have seen the locals catching them in cage traps! And yes if it hops, jumps or crawls they will eat it!mg:

 

[chav professor]

Indeed Mr Beerweasel! I have seen the locals catching them in cage traps! And yes if it hops, jumps or crawls they will eat it!mg:

Isn't that the danger of unlicenced removals.... once out of the water, they can be released, escape or what ever....

 

[noknot]

What do crays eat (bait wise) - I have experience of them eating lobworms and luncheon meat. Do they attack bread flake, cheese paste, maggots with similar gusto? can they be avoided by presenting a bait float fished??

Stocking the Lea with fish looks like it could be the only viable solution - very worrying.......

Do crays proliferate to the same extent on all rivers? Or are some more susceptable than others???

Hi Chav P, as far as I know they will eat everything! Even peanuts and tiger nuts! The only way really is to mesh your baits or a bait cage, but that will not stop them tangling your rigs, making them ineffective.......

 

[waggy]

5000, that's got to worth some $$$$$$ to somebody???
It's OK using plastic baits, but they can move and tangle up your rigs too!

All you need is an aerated holding tank and a phone number for Billingsgate. I'm sure one of the wholesalers would send out a small truck and give a good price for them.

 

[beerweasel]

All you need is an aerated holding tank and a phone number for Billingsgate. I'm sure one of the wholesalers would send out a small truck and give a good price for them.

I don't think we have them in the cam but this could be a goldmine to someone.
We are down to our last Eel catcher in the fens, maybe he should change to them.
As occupations go Crayfisher sounds pretty good, until those pesky EEs cotton on.

 

[Fred Bonney]

I'm pretty certain that most of our crayfish problems were caused by people out to make "easy" money.
They dug holes in the ground and put crayfish in. (A bit like some other puddles I won't mention)

If the crays don't like the water quality though....they walk!

I know from experience this certainly happened in the Upper Ouse area, probably 15 years ago plus!

 

[Bob Hornegold]

21 years ago I built a Golf Course for a Farmer near Towcester, he had already leagally stocked a couple of ponds with Crayfish.

To him it was another Crop, just like Sheep or Deer, I'm not sure what happened to them ?

I do know that there was a time when some Mis-guided Cat Fishermen, stocked many Ponds and Lakes with the Species and added Crayfish as a Food Source ?

Bob

 

[S-Kippy]

That’s terrible Bob, thankfully I have never encountered them on the stretches of the Colne and Loddon that I frequent YET. As tributaries of the Thames I suppose it’s only a matter of time.
Jerry

I'm amazed the Colne isn't rotten with them yet.I've seen them in the GUC around Uxbridge & Ricky and the Colne there is linked. Maybe there are still enough big fish predating them to stop them getting a proper foothold ? Pray they dont get established Jerry or its goodnight ladies.