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How Well Do Fish Recover From Being Foul-Hooked?

by Philip Monahan

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Question: It’s not uncommon on a fishing trip to have at least one foul hooked fish — some in the belly or back. Will these wounds kill the fish? Even with careful extraction, there is still a small hole in the fish’s body.

Chris Lane, via email

Trout MortalityAnswer: I put this question to Gary Grossman — Distinguished Research Professor of Animal Ecology at the University of Georgia’s Warnell School of Forestry & Natural Resources University of Georgia — and he explained that mortality rates depend on the size of the wound and the amount of tissue damage.

“If the hole is in muscle tissue,” he says, “then there probably is less risk of mortality than if the hole is near an organ such as the stomach, eye or gills.”

He notes that the hook removal process can be more damaging that the initial hooking. The wound from a small hook, carefully removed without stressing the fish, probably won’t kill a trout. But if you tear the tissue around the wound while the fish is bouncing around on stones for five minutes, you may cause either short- or long-term mortality via tissue damage, subsequent infection, and general stress.

What about the dreaded bleeding from the gills, which most anglers see as a death sentence for a trout? Grossman says that, while bleeding from the gills is bad — because the gills are organs with major blood flow — a little bit of bleeding won’t automatically kill the fish.

“One reason why I always emphasize good handling procedures — such as keeping the fish in the water while unhooking it, or just snipping the tippet instead of trying to remove a hook from deep in a fish’s mouth — is that it will minimize stress on the fish, regardless of the damage, and maximize its chances of survival. Frankly, even if a fish appears to revive fully, it still is very stressed and has a greater probability of predation or infection.”

Studies have shown that hooking location effectively correlates to mortality. As you’d expect, fish that are hooked in the lip or jaw have the highest survival rates. Fish hooked in the esophagus or gills have the smallest chance of survival. Necropsies on such fish have shown that deep hooking often causes major internal damage to the heart, stomach, or liver.

Ultimately, no matter where you hook a fish, you increase its chances of survival if you debarb your flies, keep the fish in the water, and remove the hook as carefully as possible. If it’s impossible to retrieve the hook without causing tissue damage, sacrifice the fly and snip the tippet.

MidCurrent Fly Fishing
Phil Monahan is a former Alaskan guide and was the long-time editor of American Angler magazine. He's now a columnist for MidCurrent and writes and edits the fly-fishing blog at You can email your fly fishing questions to us at
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  • Kayden

    I totally agree with this, all too often you see people ripping a fly or hook out of the belly of a trout, It is well worth losing a fly to protect a fish that may spawn in the future, or that you maybe able to catch again another day. And to the worm dunkers….hooks are cheap, just cut it off!

  • Alison

    Hooks may be cheap but they aren’t good to leave in a fish… Check out

    It explains why.

  • 7543

    My observation is that multi-fly rigs increase foul-hooking, and I don’t use them much myself — occasionally while winter midging is about it — and never when guiding. Dry-dropper is the worst. I watched too many anglers miss the take on the dry, a beat behind the eat with the hookset, and snag the fish someplace sensitive like the belly with the nymph. Then the gut-hooked fish gets fought hard because the client digs it because they don’t realize and it’s suddenly a bit more of a fight, feels like a bigger one, eh? If my client needs something to help them find a small fly in bad light, when you might put a bigger dry in front, I use a bit of BioStrike.