These species are considered edible, so are usually killed when caught. Game fisheries are restocked with hatchery-reared fish. To keep game fish safe for the anglers, fish-eating birds and mammals, together with other predatory fish, are ruthlessly killed. Once out of the water, fish start to suffocate to death. The gills collapse and may bleed.
Breathing is virtually impossible.
During the period the fish is out of water it must live without oxygen. If a fish is kept in a keepnet, they will also suffer from lack of oxygen in the water within the net, they may be damaged by other fish, and they may catch diseases from any other sick fish in the keepnet. The suffering doesn't end there. Smaller fish are impaled on hooks as live-bait, and other animals are maimed and killed by the hooks and lines left behind by anglers. Anglers are often careless, and on the bankside leave rubbish like drink cans and bait cans with jagged edges, as well as plastic bags.