Cormorants don´t do much damage to individual fish. The damage is that they eat so many, and that their numbers have increased rapidly to the extent that they can strip some waters of fish in a remarkably short time.
Change of habits, and habitat has also proved disastrous.
You will find more fish damaged by pike and herons, although some instances of scarring by cormorants are known.
"Cormorants don´t do much damage to individual fish."
Sorry Mike but you're right in that they eat a lot of fish but those that fish some of our resrvoirs will testify that there are a huge amount of fish caught bearing wounds to their flanks where they have been attacked by a cormorant.
Some of the fish I have caught are so bad they look inedible (guts visible) and these are invariably fish that are around 2 - 2.5lbs in weight.
I can get you some pics dunc when the season gets underway.
"Cormorants can damage and scar fish, especially larger ones which they fail to catch properly. This can increase the risk of disease, mortality, stress and behavioural changes (fish become more difficult to catch). Anglers’ perceptions of cormorant damage at a fishery can result in a fall in income from permit sales and in the value of the fishery (regardless of whether a ‘serious problem’ actually exists)."
I think a lot that is written about cormorants is RSPB led.
I'm sure it was John Wilson who commented on a programme filmed at Rutland whilst in a bird hide about the huge number of cormorants he could see. The tongue in cheek reply from the Chief Twitcher was "What cormorants?"
Over the years at Farmoor I've had quite a few fish that are badly damaged, some with holes right through them, I don't think its Herons unless they wade out on stilts. A lot of the damage is done by cormorants over the winter when there isnt so much other activity on the water, or when the first stocking takes place when its easy prey for them.
I agree with Gillaro on this one. Cormorants do damage a lot of fish, at Wally sometimes I have caught six or so in a day and they have all exhibited the kind of damage shown above, over the course of a season perhaps 50% (low estimate) show this. It would be wrong to say that they rarely miss, in nature predators have quite a high rate of unsuccesful hunts. If they were hitting a 90+% success rate they would have been so numerous as to have never needed protection. As an aside I caught a Jack pike on the Lee and it too showed this damage, the birds appear to be in the process of decimating stocks there as well, judging by the number I have seen and the relative lack of coarse fish, they must be forced to go further afield when wally's stock levels are low.
Were you going to do anything useful/in particular with the pictures? Like Gilaroo, I might come across a fish or two with cormorant damage. I could photograph them and post them up for downloading. I caught some last year with puncture marks that weren't pike damaged and almost certainly cormorant damage.
As a part of my catch I'd say that cormorant damaged fish form a tiny proportion of my catch ( not that I catch that many ) On Rutland the gill parasite is more of a problem.
My local water apparently has a cormorant, but I have not seen it. I have however seen some scarred fish recently. Not long slash marks, more a round hole type scar. The last fish I caught like this splashed around a lot but had no pulling power in the fight.
There is a river next to the lake, although I would think it would not be at too much risk, having a stocked fishery right next to it.
If you talk to any of the long term anglers at Rutland , the waters coarse fish population has been decimated by cormorants, youhave some big fish, this years fry and not much in between, they have been scoffed by the cormorants.
Colwick Water in Nottingham has changed its stocking policy this year... less fish, but all above 2lbs. This is to try and stop the numbers being eaten by these d**n birds. Hopefully, they wont quite manage to lift the bigger ones.
I have caught plenty of overwinter trout with scars, and you only have to glance at some stones near the entrance to see them sat waiting. The place is full of birdwatchers, though. I hate those d**n Canadian Geese, too. They should be culled. Just like pigeons.
There, that's said it. In fact, hunting them with hounds sounds a good idea? On horse back might even be fun?
Why has the cormorant population exploded? Or have the birds just found new hunting grounds?
Generally speaking, populations tend to be regulated by the available food supply. There is less fish available for them in the sea, but more fish available inland supplied by stocked fisheries, hence the decline at sea and the 'explosion' inshore.
By the way uk Steve7, stocking larger fish may prevent them being eaten, but it won't stop them being damaged by cormorants, as the picture I posted above clearly demonstrates. The fish in the photograph was over 2lbs.
Happier those that go out to please themselves, and not to astonish others. R.S. Surtees