I have cut and pasted this article for you Wallsendo
The Acid Test
All fish have a built in mechanism that will help them survive a hook. The larger the fish, the better the mechanism. Their body fluids contain a substance that can literally dissolve a hook within a matter of days. I have caught a number of large fish wherein an imprint of a hook can be seen inside their mouth cavity. The hook is gone – dissolved – but the outline is still there. I’ve cleaned fish and found the same thing in their stomach lining. Biologists I have interviewed in the past have provided me with data indicating the high acid content that dissolves the hook.
The Release Process
Given that these fish can dissolve the hooks relatively easily, the best method for releasing becomes obvious. I cut the line or leader off the hook as close to the eye as possible. Fish hooked in the gills are less likely to survive, but leaving the hook in place is far better than trying to remove it. Fisheries biologists confirm that the survival rate is extremely high if we simply leave the hook and cut the line.
Did you ever notice that fish hooked in the mouth area or in the stomach area never bleed? Bleeding fish will invariably be hooked in the gills, where their blood flows to gather oxygen from the water. The mouth area does not bleed. Fish are constantly being poked and stuck during their normal course of feeding. Larger fish, feeding on smaller fish are constantly being stuck in the mouth area with dorsal and anal fins – and painlessly, I might add. A hook is simply another fin to them.
Once the line is cut, I will make sure their air bladder has not been distended. If it has, a small puncture with a needle or the point of a hook will allow the pressure to equalize, and they can then swim back to the bottom.
Handle the fish as little as possible and make this a quick return to the water.
Another Option
One way to insure good releases is to avoid gut hooking a fish. Sometimes we can’t avoid it at all. But the use of circle hooks can make a big difference. Circle hooks are designed to hook the fish without the need for you to set the hooks. In fact, if you set the hook you will usually end up missing the fish. As the fish swims away with the bait, the circle hook and bait begin to be pulled from the mouth or stomach of the fish. As the fish feels pressure, he swims faster and the circle hook ends up at the corner of the mouth. It works this way a very high percentage of the time. Gut hooked fish are rare when using circle hooks.
Summary
In the future, take the time to allow a fish to live to fight again another day. Give up the few penny`s it cost to replace a hook and let your released fish take care of it. Future generations of anglers will thank you!
Hopefully some info there for you
This is what this Board is for - Helping each other and keeping us fishing
Cheers BriH