Colin Mitchell, our weekly pleasure fishing blogger, looks at catfish. Please share this blog on Facebook and Twitter by clicking the icons above.

BIG catfish appearing in England’s rivers have hit the headlines in Angler’s Mail magazine recently – and no surprise that’s created a bit of controversy.

So, are moggies in Britain’s flowing waterways good or bad news for anglers? I’m going to put my neck on the line a little here and say they could be good!

Now before someone gets the guillotine ready for me, let’s have a look a little more closely at this…

Ryan Lippitt showing off his latest catches.

Zander are in many rivers and canals, but they appear to have ‘settled down’.

Zander caused a scare too

A few decades ago the importation of zander into the Fens caused uproar. The red flag was raised with fears that this predator could wipe out huge sections of waterways and eventually decimate sport across the country.

There’s no denying that for a time the zander did make inroads into native fish stocks in some areas. There were official culls and some fish probably did get taken for the pot too.

But now zander are quite widespread across the Midlands and even into southern venues, including the Thames.

Some anglers can even take you to spots on the Thames with the aim of catching the species. No one now appears too worried about this spread. In fact zander have become a species of choice for some anglers.

And in some rivers, like the Severn and Warwickshire Avon, they have reached specimen and record breaking proportions. That lower Severn 94-pounder was something else!

So why should be worry about the catfish?

All-rounder Colin Mitchell with a catfish

All-rounder Colin Mitchell with catfish

Ok, catfish are not native and we won’t condone any illegal stocking of the species.

Most likely some of these fish have found their way into rivers illegally but others will have been swept into venues as stillwaters have flooded.

In the Severn and Thames we know they have already hit specimen proportions. Whether they will grow much more depends on what food is available and also water temperatures.

But at the end of the day Mother Nature will decide what happens – just like she did with the zander. Every species – even roach, carp, pike, perch etc – all find their own levels in a fishery.

It’s down to breeding, survival and predation as much as anything else. Cats won’t breed unless the weather and water conditions are right.

Likewise they won’t grow unless there is enough food.

I have seen stillwaters in England where the introduction of cats has seen the original stock fish depleted… but then bounce back after a few years. It’s nature doing what she is best at.

There are other venues where the cats have actually eaten their way through some of the stock but the tougher fish have survived and grown into specimens themselves.

Kittens would be a really worrying signal

I can’t – at the moment – see the day when I can nip down the Thames or any other English river venue and bag myself a catfish, unless I invest an awful lot of time and effort.

Blog MitchI know good anglers who have tried fishing for months in areas where cats have been caught on the lower Thames and failed to attract their intended quarry. The first catches of a few ‘kittens’ on any river will be the sign they are breeding rather than just the odd fish lurking and growing big.

That could be the time we worry. Or it could be the time we start to believe we have a new established species.

On mainland Europe cats are a common sight on many rivers. And those venues also appear to hold vast numbers of fish like roach and bream… they haven’t been munched out of existence.

Spain’s Ebro is stuffed with monster catfish – and yes they do still catch carp there and in recent years some monster roach too.

There is no good reason why the cats can’t live in England too!