Friday, 8 November 2013

Canal Roach — A Signal Defeat?

Well the roach session did throw up a surprise, but a nasty one. Bream were biting and I had a couple of them as always but no sign of roach in the first chosen peg. Bites came around the half hour mark, which is usual for bread fished over mash, but then they tailed off and didn't look as if they'd return.

Second peg bites came after five minutes, but once again bream were the culprit. However, a few tentative sharp dips around the half hour mark put me on guard for the desired big lift of the float from feeding roach. But, it never came...

When recast the float refused to settle down to the tip as it should but stayed aloft, the final shot placed just an inch from the bait had not hit bottom. I thought it had landed on a twig which would produce the same effect but strangely the float seemed to be moving slowly and steadily to the left.

Not something I've ever seen before, I left it to continue and when it crossed into the deepest part of the boat track the float very gradually vanished. A moving twig? Surely not.

There was nothing there. No twig, no branch, no nothing, moving or not.

It happened again, and again. And then finally I hooked the twig, and it felt like one too, even looked like one for a brief moment...

Gimme a big hug...

Ah no. Not you!

I thought I'd never see signal crayfish penetrate so deep into the city territory of the Coventry Canal with its almost unbroken steel revetments and hard packed towpath banks. Unfortunately there's gaps along the far bank, here and there, where the banks meet the waters without a barrier between and that's all the buggers need to breed and survive.

Jesus, they exploit watercourses with gay abandon, don't they. No doubt they'll be crawling up the drainpipes next, taking up residence in the lavatory pan, eating our turds and thriving too.

Is nowhere sacred...?

There's just no answer to them, you know. Simply no way to control let alone eradicate them. Everything tried has failed — successes have been brief and rebounded badly. Research continues but it's wasted time, effort and money. Nothing works.

The only thing that has not been tried, as yet, though many think it the only viable way forward, is Sterile Insect Technique. Hoards of sterile males are released into an environment overrun with a plague of an invasive or damaging species, they outcompete fertile males due to their greater numbers, breed with fertile females who then lay infertile eggs.

The life cycle of an insect can be broken, indeed screwworm was completely eradicate from the 176 square-mile Venezuelan island of Curacao in just seven weeks. However, the female of that species mates just once in her life...

Crayfish just go on and on.

I'm sure it would be tried with them on a trial basis at least, if only a way could be found to chop the boy's nads off. No one has succeeded in doing that yet. I wouldn't know where they were in fact I can't tell the difference between the boys and the girls.

I've heard they can hybridise with native crayfish, though, or at least they can mate with them. I cannot find hard non-contradictory fact about whether or not they actually can produce offspring or just infertile eggs. Some authorities say the one thing, some the other.

But if hybrid offspring were created they would be infertile, wouldn't they?

So, find out if that is true, breed trillions of these saviours, eat the females, release the males en-masse into every place, and kill the signal bastards off!

(Take out the native crays first though! If you can find any...)

The cost though. That's what stops progress. It's not that it wouldn't cost a lot to do — it would. It's that the plague doesnt cost the economy enough to warrant it.

Only when so chock full of them the culverted Tyburn pops its manholes and overflows into the streets of Westminster, The Embankment is so deeply undermined by breeding burrows that Big Ben lists militantly to the left, and our Prime Minister gets his nads bitten, on the khazi, 10 Downing Street, will anyone do anything about them.

Till then, they're here to stay.


  1. Crayfish seem to be infiltrating the most hardy of waters, they thrive so well in the Mole the bottom is merely made of stones in some places but the carapace of thousands of Crayfish, eat them all I say and what ever you can't take home with you, cleanse them with the dignity they deserve, to a lighter note, it's a shame you didn't find a Redfin, but I have no doubt come the cooler months you'll find them and dare I say it, one of the sort that George had??.


    1. I might put out a trap, see what it brings James. I think some of the damage to your sprats was probably crayfish. I'll find the roach soon enough. Just keep hopping here and there and watching for signs around dusk.

    2. Additional to what you've said, James, those who've not yet encountered a properly infested river have no idea just how many can squeeze into one. The Blythe near me is similar to the Mole. They'll take trotted maggots a foot above the deck once they learn how to intercept loose feed! When chub fishing you know a fish is nearby because the tip remains still, otherwise it's moving the whole time. There's literally hundreds in every swim. Makes fishing a nightmare...

    3. Hope it's just a stable population now in the canal Jeff and not on the increase. If it gets to the level of numbers like are present in the blythe it would make any type of fishing a nightmare. Wonder if the zeds eat them they certainly have the mouth for dealing with them!

    4. Lets hope so Lee. I'd never seen one on the Coventry Canal till last year when I hooked my first. Since then I've had three more, so they've arrived around these parts quite recently. Hopefully they'll not have the breeding opportunities they have on the Blythe and stay a background nuisance. Hope so, because as you well know, the Blythe is a nightmare in many places where fishing just isn't worthwhile anymore.

      I suppose that zander will eat anything judging by the nasty baits I've caught them on! Refrozen over and over dead roach bits and pieces I've already used, they'll have all that ta very much! I think they are part time scavengers. I also hope they find the young crays to their liking like perch do. Only a pike could tackle a big one, I reckon.

      Be great if zander do like them. They wiped out the canals gudgeon, maybe they'll control the signals?

      Maybe zander might be the answer if so. Then again I heard that eels were the crayfish eater par excellence. They are returning in numbers after a terrible crash.

      What would you prefer though, stacks of eels, or stacks of crayfish!

  2. Jeff,

    I feel your pain:-(.Like James has mentioned on my local river the Mole they can be horrendous.Trapping has done very little to eradicate the problem,it is a case of "up sticks" to get away from the buggers.Some swims seem to hold more than others.

    1. No, trapping has been a disaster, Monty. On trials it's been found that it only serves to reinforce recruitment survival rates. The trapped adults are taken away, but all the hard to trap tiny juveniles slip through the meshes and survive in the absence of their cannibalistic uncles and aunts. The only way to do it is on a commercial basis when the trapping rate is determined by constant and regular market demand. Then again, when was the last time you saw crayfish available in supermarkets?

  3. You don't Jeff but there's a hole in the market and you've just found it!, come up with a business plan and you could make a few quid they taste good, just when you prepare them don't eat or cook dead or dying ones, sounds rough but alive into a boiling pot is the only way to do it, the rivers in the south that have crays do usually hold monster Pike and Perch, usually where the crays are, there be predators! So they do have one use.

    1. Unfortunately, it seems impossible to make a business from it, James. The rules and regs are so constipated that it's impossible to do it. The problem is the native cray! If it were extinct it would open season with nothing to protect, but because it still exists no one can trap commercially for fear of them moving signals into unsullied native territory.

      At least that's what I think is the problem! It's hard to get to the bottom of.

      See George's comment further down. I think as a member of a team you can do it, but there's no team up here, so we can't.

  4. Interesting you talk of sterile crays being introduced they were quite well advanced recently in the "daughterless carp" project in Australia. Makes more sense than most eradication solutions although it would take a generation to see any real results.
    Surprised some clued up bait maker hasn't started using signal crayfish as a bait ingredient instead of fishmeal , could show how pro environment they are. I would imagine getting a steady supply could be an issue. But still if they breed in such numbers and sustain high enough populations I cant see why there would not be a opportunity somewhere.
    Rob Ballarat

    1. That's really very interesting, Rob. Just read a potted account at that explains it very well.

      As always, what fails a great idea is the 'Health & Safety' dimension of putting it into practice in the real world. So many mistakes in the past, and Oz is a continent that knows all about them! so nothing progresses for fear of making things even worse. Therefore it remains in the lab as a work in progress...for ever!

      I fear that's what will happen here. Then again the local canal is so full of non natives — zander, zebra mussles, signal crayfish, that the worst may be done already. I suppose we'll just have to wait for a balance to be struck.

      As for bait. I think I'm within the law using them. Well according to the rules I must destroy any I catch 'humanely' so I have to kill them. What I can and cannot do with the corpse is not at all clear!

  5. I applied for a licence to Defra and was refused as C&RT do not allow trapping. I contacted C&RT to be advised that as I was not a 'responsible organisation' I was not a suitable applicant

  6. Last season on the Kennet I met a licenced trapper Jeff, he said the price he could get was so low it was no longer worth his while.

    As for using them as bait,I think that is illegal, especially if alive!
    They are good boiled in a little dill flavoured water and then dipped in a Marie rose sauce.

  7. If there is money in trapping crayfish.. then some people will transfer live crays to their waterway so they can make money too.