Last summer I fished the West Ranga in Iceland.
They encourage taking fish there.
All the males are killed and the females are kept for their eggs. For each female caught you are given a side of smoked salmon.
The reason for this is that all the fish in the river are hatchery fish and apparently because of volcanic activity several years ago there are no real spawning grounds for salmon.
My wife thought it was great that I came home from a fishing trip with some fish.
I am normally an exponent of catch and release but I do not have qualms about taking fish on occasions.