Catfish

108831

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Catfish eat absolutely anything and regardless of their small eyes they see well,they see pigeons land on the bank for a drink and try to predate them,imo they are not a good thing for any water,the water I fished for several years had a good population of cats from kittens to around 70lbs,though there were fair amounts of tench,bream,carp,perch and pike they predated roach in the main,which they come up on from below and suck in a bucket of water and any roach in that,from up to a yard away....
 
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sam vimes

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I suspect that the best anyone could hope to achieve in the bigger rivers (Severn, Trent and Thames) is that a lid be kept on catfish populations. The only upside I can think of is that EA policy on non-native fish introductions is now much more stringent and evenly applied than it once was. There aren't that many fisheries that are officially sanctioned to contain cats. I only know of a couple of places within fifty miles or so that have legitimate stocks of them. I know of a couple a little closer that might have a couple of illegal cats. One managed to end up with them unknowingly. Nowhere I actually fish with any regularity has them.
 

no-one in particular

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I do stress this is not based on anything scientific just a layman anglers view of it.
The best their is in my opinion, better than a scientist can predict with their computer models and number crunching etc. I am sure this is the case with the sea, we know what's going on long before they do and I am pretty sure it is the same to what's happening in our rivers.
 

108831

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One problem I do have however,is knocking one on the head,I do not agree with humans interfering with nature,but we are responsible for their introduction....
 

steve2

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Knocking fish on the head isn't something we do in this country so we will keep on returning them. Who is going to be the first of us to knock a 50lb catfish on the head and throw it up the bank like some anglers still do with Pike.
 

tigger

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One problem I do have however,is knocking one on the head,I do not agree with humans interfering with nature,but we are responsible for their introduction....


Would you have a problem shooting a rat Alan?
 

silvers

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The best their is in my opinion, better than a scientist can predict with their computer models and number crunching etc. I am sure this is the case with the sea, we know what's going on long before they do and I am pretty sure it is the same to what's happening in our rivers.
You should try reading up in Beverton Holt model and the foundation of fisheries science.
The problem is not the science, it’s the political will to implement policy (See 2020).

For interest ... the origins of the equation were written on the back of an envelope on top of a tank in Normandy in 1944. lots of ministry scientists were in op research for the war effort.
 

tigger

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Knocking fish on the head isn't something we do in this country so we will keep on returning them. Who is going to be the first of us to knock a 50lb catfish on the head and throw it up the bank like some anglers still do with Pike.


I wouldn't hesitate to do just that. I may cut it up and use it for the dogs rather than waste it.
 

no-one in particular

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You should try reading up in Beverton Holt model and the foundation of fisheries science.
The problem is not the science, it’s the political will to implement policy (See 2020).

I tried and decided it is better to go fishing instead to see how many catfish there are, after having a very lay down that is.:)

The Beverton–Holt model is a classic discrete-time population model which gives the expected number n t+1 (or density) of individuals in generation t + 1 as a function of the number of individuals in the previous generation,

n_{t+1}={\frac {R_{0}n_{t}}{1+n_{t}/M}}.

Here R0 is interpreted as the proliferation rate per generation and K = (R0 − 1) M is the carrying capacity of the environment. The Beverton–Holt model was introduced in the context of fisheries by Beverton & Holt (1957). Subsequent work has derived the model under other assumptions such as contest competition (Brännström & Sumpter 2005), within-year resource limited competition (Geritz & Kisdi 2004) or even as the outcome of a source-sink Malthusian patches linked by density-dependent dispersal (Bravo de la Parra et al. 2013). The Beverton–Holt model can be generalized to include scramble competition (see the Ricker model, the Hassell model and the Maynard Smith–Slatkin model). It is also possible to include a parameter reflecting the spatial clustering of individuals (see Brännström & Sumpter 2005).
 

silvers

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To be fair ... the history of the people involved is more interesting ;)

That equation is the basis of all modern fisheries science. the bloke who wrote the original equation on top of a tank was a relation.
I do agree that fishing and angling in particular can provide a very good early indicator of problems ... but we can’t scenario model the effect of different management approaches on the populations.
 

mikench

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Knocking fish on the head isn't something we do in this country so we will keep on returning them. Who is going to be the first of us to knock a 50lb catfish on the head and throw it up the bank like some anglers still do with Pike.
I won't return one if I'm unfortunate enough to catch one.
 

108831

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Would you have a problem shooting a rat Alan?


Not at all,but a rat is vermin and carries disease,why don't we shoot the human who was responsible for the catfish's introduction...
 

108831

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I won't return one if I'm unfortunate enough to catch one.

Not if you wanted to stay in the clubs that are happy with their presence you wouldn't,the water I caught my 30lber on roach gear, only succeeds because of catfish anglers memberships,Leighton Buzzard angling club is in a similar situation....
 

108831

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I don't think you could,cruelty issues would creep up on you...
 

mikench

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Non of my 3 clubs have authorised catfish and most don't have any at all. I wouldn't broadcast the fact as I don't with vermin removal. One club card has a day ticket water on it which has cats. I've never been and never will. I will destroy signal crays whenever I come across them.
 
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