This overlooks the fact that the process of catching and removing a fish from the water causes a great deal of suffering. The fish is hooked through its lips which like the rest of its body contain lots of nerve endings, meaning that it feels pain when hooked. After being pulled out of the water into the air, the fish starts to suffocate, just as we would if we were pulled under water, because the fish can not breathe in air. Anglers often like to take photos of big fish, which lengthens the time the fish is suffocating before being returned to the water. The fragile mucous layer.
Fish also have a delicate mucous layer covering their scales to help guard against infection.
This can be easily damaged during handling out of water, even when using wet hands. If damage is caused to this invisible layer, it leaves the fish vulnerable to disease when it is returned to the water. The killer keepnet. As mentioned earlier, fish may be put into keepnets after they have been caught. It is easy to see that angling causes suffering to fish regardless of whether or not the fish is returned.