Grundulis, that's called a gill net nere in the states. You can buy them, they come in different mesh sizes to target certain sized fish.
Thanks for information.
I think that this is the best way if you got a boat but it's not impossible to use it without boat too. Such gill net is very efficient and in case when pond is overpopulated it might be the best way.
Sure, it has some disadvantages too. For example, it catches all the fish of certain size without any sorting. But... it works alone and you got only a little to do:
1) set it;
2) collect it and remove all fish.
And set it again
Good luck.
