Otters and signal crayfish

[rayner]

The crays are here to stay, we will never be rid of them unless we kill the waters they are in. Can we bear to kill everything in the water to rid the waters of Crayfish? Is there an alternative?

 

[mikench]

I have déjà vu at the moment. Could the song " I know an old lady who swallowed a fly" help?

 

[The bad one]

The crays are here to stay, we will never be rid of them unless we kill the waters they are in. Can we bear to kill everything in the water to rid the waters of Crayfish? Is there an alternative?

Sadly that's true in the main, but there are relic populations as the one I've mentioned that are monitored vigorously by the EA and wildlife trusts and action taken if signals are found in the area. They seem to be holding the line and have been for sometime. It's much the same for Red Squirrels in the same area. They have dedicate Grey Squirrel wardens that actively go out and shoot the horrible tree rats. All the locals are well drilled about what to do if they see a grey and who to report the sighting to.

 

[no-one in particular]

Its all here to stay, once anything has got a foothold it is almost impossible to eradicate them. I was trying to think of an example but I cant. Maybe rats on some small island but that took a concerted effort and years to do. Can't see it is possible over such a wide area as the whole country. And the "experts" are still introducing stuff willy nilly on natures/our behalf. Or "accidently" introducing them. Ha

 

[108831]

Apparently signals run in seven year cycles,when on the down slope the numbers go right down,then surge back again,poxy things....

Phil,we used to have a population of white clawed crayfish on the grand union canal at Leighton Buzzard,near the Globe Inn,Linslade,the little sods used to bite holes in my knotted keepnet to get my hard earned gudgeon,when I was 15,back in prehistoric times...

 

[Keith M]

There were some of our native White Clawed Crays in a stream running into the Grand Union Canal just to the north of Watford back in the late 70s as when I was trying to net a millers thumb and a stone loach in the steam to show to my son I caught a couple of them.

Keith

 

[John Aston]

30, 000 it beggars belief but I have seen it myself. A quick acting poison that becomes non toxic very quickly is what is needed, you could go down a stretch, electro net all the fish out and store, introduce the poison at the top of the stretch, kills all the cray fish and becomes non toxic before it enters the next stretch, put the fish back and work your way down the canal or river. It would have to kill cray fish only though. maybe I need to go fishing

A career in physics beckons ... let us know when you've cracked the miracle formula eh ?

 

[ian g]

Fishing the Severn around Shrewsbury I've seen plenty of otters over the last few years . I've haven't seen any of the fish heads etc that seem to be common on carp lakes with otter issues but you do see lots of discarded mussel shells on the bank . Suggesting fresh water mussels figure regularly in their diet.

 

[The bad one]

Its all here to stay, once anything has got a foothold it is almost impossible to eradicate them. I was trying to think of an example but I cant. Maybe rats on some small island but that took a concerted effort and years to do. Can't see it is possible over such a wide area as the whole country. And the "experts" are still introducing stuff willy nilly on natures/our behalf. Or "accidently" introducing them. Ha

Again in the main you are right Mark. I can only think of one and that was Coypu on the Fens. Rather ironically at the time they announced the eradication of them, me and a mate later in the month were zander fishing on Welney marshes and running across the mash towards Downham Market was a coypu. My mate saw it first and says, “what’s that running there?” To which I stated laughing and said, "it is a ghost of a coypu." "English Nature claimed earlier this month they’d eradicated them all." They either caught up with it later or it died because I've never heard of one since on the Fens. Neither has my lad who live very near the Fens and drives all over them every day.

 

[steve2]

One thing that always puzzled me is just how fast they spread. But then I read that people were moving them in order to boost the size of fish.
That still didn't explain how they got into waters in the middle of nowhere with no fish and no links to rivers. A bit like how do fish get into ponds.

 

[no-one in particular]

Again in the main you are right Mark. I can only think of one and that was Coypu on the Fens. Rather ironically at the time they announced the eradication of them, me and a mate later in the month were zander fishing on Welney marshes and running across the mash towards Downham Market was a coypu. My mate saw it first and says, “what’s that running there?” To which I stated laughing and said, "it is a ghost of a coypu." "English Nature claimed earlier this month they’d eradicated them all." They either caught up with it later or it died because I've never heard of one since on the Fens. Neither has my lad who live very near the Fens and drives all over them every day.

We used to see them around Sunbury Island on the Thames, whether they are still there or elsewhere I don't know but I have never seen one since anywhere else so, they could have been completely eradicated. I think they are nocturnal though so some could be hiding somewhere, that's when we used to see them as we used to fish all night on the island. People often thought they where giant rats. Animals are clever at hiding away, you would think beavers would be easy to find, their homes are pretty obvious but I think they are struggling to find ones that escaped along the Adur and the same thing happened in Scotland, I don't think they found them either.

 

[108831]

Crayfish are massive egg layers and also march along drains and dykes,tiny streams etc,they survive out water especially in rainy conditions,they too are like crabs,having to peel to grow,so come out of the water,one evening on the Kennet after a days fishing a mate and I walked back along the bankside path and virtually every footfall was met with a crunch,signals were everywhere,a bit like slugs.... ?

 

[no-one in particular]

Crayfish are massive egg layers and also march along drains and dykes,tiny streams etc,they survive out water especially in rainy conditions,they too are like crabs,having to peel to grow,so come out of the water,one evening on the Kennet after a days fishing a mate and I walked back along the bankside path and virtually every footfall was met with a crunch,signals were everywhere,a bit like slugs.... ?

Just been reading about a survey done on a place where these were present to measure the density of them where they had been illegally released. It was done meticulously, even going to the trouble of temporarily removing boulders etc.. It was 110 crayfish per 1sq meter in places; extraordinary.
Sadly it concluded that there was no answer, even trapping only got a small percentage of them.

 

[108831]

I fished two venues this closed season quite often where crays are prolific and are trapped,you can see them strolling about,I haven't had one,nor had any fall off,some of the baits used are fishy,so very attractive to them,must be my aftershave...

 

[no-one in particular]

I fished two venues this closed season quite often where crays are prolific and are trapped,you can see them strolling about,I haven't had one,nor had any fall off,some of the baits used are fishy,so very attractive to them,must be my aftershave...

They said something about the smaller crays escaped traps so they carried on breeding. I don't know, just what it said. I guess on some lakes it is easier but on rivers must be nigh impossible. I think the reference to it being impossible must have been on a national basis.

 

[John Aston]

Crayfish 'strolling about' - a great image . It reminds me of the immortal quote from the 19 th century French poet who walked a lobster on a lead through the streets of Paris , and explained why - "He does not bark and knows the secrets of the deep ."

 

[no-one in particular]

Crayfish 'strolling about' - a great image . It reminds me of the immortal quote from the 19 th century French poet who walked a lobster on a lead through the streets of Paris , and explained why - "He does not bark and knows the secrets of the deep ."

Poetry and crayfish this early

 

[Keith M]

They said something about the smaller crays escaped traps so they carried on breeding. I don't know, just what it said. I guess on some lakes it is easier but on rivers must be nigh impossible. I think the reference to it being impossible must have been on a national basis.

You will find hundreds of eggs attached under their bodies amongst their legs and they will shed them quite easily through the traps.

The Turkish Crays that we had in our lake spread downstream from a reservoir above us back in the early to mid 90s; where according to various people who fished the reservoir a lorry (on its way to deliver them to restaurants) was allowed (by some idiot) to keep them temporarily in a cage submerged into the reservoir because their oxygenation equipment broke down. The rest is history.

We applied successfully for a licence to trap them and have been trapping them for around 30 years with very little success, we even had a university come down to trap some for their experiments on how to eradicate them (which failed).

We now no longer have a crayfish problem (Hooray!) ever since someone stocked some catfish illegally (without our knowledge) into our lake; and now we are having to get rid of the catfish who it appears have started to feast on some of our other fish; (now that it seems they have eaten all the crayfish; which isn’t really a bad thing as long as we can now rid ourselves of the catfish).

Keith

 

[no-one in particular]

I think a catfish problem is less of a problem than crayfish and would work on a lake as long as you can get rid of the catfish which should be possible. On a river or canal it would be impossible to rid the catfish I would think. However, I would still rather have a catfish river and less fish than crayfish, at least I would still be able to fish properly and they are not so damaging to everything else in the river and at least I could take up fishing for catfish if nothing else; crays just ruin it full stop in my opinion.

 

[108831]

But some waters get stocks annihilated by cats,then you would have nothing to fish for,this hasn't occurred in waters that i've fished with cats,but....