Keep nets are something I absolutely detest. However you see them all the time on commercial carp waters and I just wish the fishery owners would put a complete ban on them outside of fishing matches. Over the last two or three years I have seen the same people constantly using keep nets at one of the venues I go to. I've observed them throughout the day putting every carp they catch into their keep net. However, at the end of the day when they are packing up, all they do is take the net out of the water and empty all the fish back into the pond. Exactly what is the point of this? Even though I don't agree with keeping carp cooped up in a keep net for several hours, I could sort of understand if somebody wanted a nice photo of themselves lying on the bank behind a huge haul of carp, at least they'll be doing it for a reason. But no, the only thing I can think of is these people are doing it because they want to show off in front of all the other anglers, hey, look how many carp I've caught!
I honestly don't think some of these people are taking the carp's welfare very seriously. Fish do not like to be all huddled together in the keep net where they can't move. In the summertime when it's warm the water can often be lacking in oxygen. Anglers who insist on using keep nets when it's very hot are not thinking about the carp's well-being at all. If a fish cannot move around properly in hot weather then it could possibly die of hypoxaemia, this is a lack of oxygen in the blood. Under no circumstances should carp ever be kept in the keep net in warm weather. In fact you should forget about keep nets altogether during the summer time in my opinion.
Finally, there is the question of fairness. Everyone pays the same money to fish at a commercial water. Is it really fair of one guy to keep a large number of the ponds fish in his keep net just for his own ego? If there are 200 fish swimming around in the pond and I have paid £7 to fish that pond, I want to be fishing for 200 carp, not 120 because a few guys have got them all in their keep nets.
If you are an avid keep net user then please think very carefully about what you are doing. Why do you feel the need to put every carp you catch in the keep net for the whole day? Do you honestly think that it's fair on the fish? I would ask these anglers to please leave their keep nets at home and only use them for when they are taking part in fishing matches. You are not impressing anyone by keeping the whole day's catch all cooped up in the net. All you are doing is causing the carp a lot of stress.