A case for cormorants?

bleak · Feb 17, 2011

There is a lake near me(france) of about ten acres, the water plants have been ravaged by coypu,and the only fishing I have seen done there in the past ten years is the locals catching pike and zander which are always taken away to be eaten. What is left is a huge amount of carp and silver fish, all remain very small eccept for the local 'crucians'which grow to good size. When I saw the first comorants arriving I wasn't happy.However could this cull actually thin the population and help the fish to grow bigger.?

Jeff Woodhouse · Feb 17, 2011

When you titled the thread "A case for cormorants?" I thought you were looking for a glass case to mount a dead one or two in!

To answer your question, all depends on how many cormorants you get. A couple, three maybe - yes it could thin soem of the small fish out and allow other to grow bigger. One hundred and sixty four nesting, breeding pairs, NO - total decimation.

Lord Paul of Sheffield · Feb 17, 2011

Jeff Woodhouse said:
When you titled the thread "A case for cormorants?" I thought you were looking for a glass case to mount a dead one or two in!

To answer your question, all depends on how many cormorants you get. A couple, three maybe - yes it could thin soem of the small fish out and allow other to grow bigger. One hundred and sixty four nesting, breeding pairs, NO - total decimation.

That's a very precice number Jeff

chav professor · Feb 17, 2011

Hell of a lot worse than otters. They can move from one water to another and decimate small fish stocks. probably more sgnificant, I have a theory that predation by both otters and comorants changes the behaviour of the fish. there are sections on our river where fish used to be seen basking in open water - they are now absent.

you can find them, but only where there is adequate tree canopy cover presumably to avoid comorants.

Must make spawning on shallow gravel nearly suicidal..............

mol · Feb 18, 2011

A good friend of mine has fished the Seine for a long while. Before the comorants arrived a match would be won with 30kg+ of silvers, the silvers have almost disappeared now and been replaced by bream. Maybe the comorants are to blame or maybe it's just the changing ecology of the river?

Finding good sized silvers does seem to be a problem on alot of lakes around me, it's either hundreds of small fish or massive bream shoals.

thx1138 · Feb 21, 2011

chav professor said:
...I have a theory that predation by both otters and comorants changes the behaviour of the fish...

I think Charles Darwen has beat you to that theory mate

irfonminnow · Feb 22, 2011

james said:
I think Charles Darwen has beat you to that theory mate

Beat me to it!

904_cannon · Feb 22, 2011

But Darwen wasnt of the 20th/21st Century. Neither did he have a massive destruction of sea fish stocks to contend with in his thinking.

We are lucky on the Wear in Durham Jeff. there are only 116 breeding pairs

YouTube - Durham City - Cormorants

thx1138 · Feb 22, 2011

john m h said:
But Darwen wasnt of the 20th/21st Century. Neither did he have a massive destruction of sea fish stocks to contend with in his thinking.

True. Although his thinking was formed during the swing of the industrial revolution, a time when our rivers were in massive decline due to pollution. And there was nowhere for the fish to hide.

Peter Jacobs · Feb 22, 2011

There can be only one applicable 'case' for Cormorants, and that is a:

CARTRIDGE CASE!

AS EASY AS, AND END OF

Merv Harrison · Feb 22, 2011

john m h, the piece of timber in the foreground with the blue twine, what's fastened to it...dynamite ???.....simples

MarkTheSpark · Feb 22, 2011

Jeff Woodhouse said:
One hundred and sixty four nesting, breeding pairs, NO - total decimation.

Tut tut, Jeff. Decimation is so often used badly; it actually means 'reduced by one tenth' so not what you meant....

The bad one · Feb 23, 2011

I really think you should read Darwin before you misrepresent him. tut tut!
The Origins of Species is about Evolution not Adaption.
Evolution takes many thousands of years, whereas, Adaption can happen in tens.
And I don't think his theory, observed and developed in the Galapagos Islands was done against the backdrop of any industrialisation whatsoever on the Islands.

The nearest to any industrialisation was the slaughter of the the Giant Tortoises on several of the islands, which came after Darwin's visit by mainly British sailors for food

A case for cormorants?

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