I once landed a good small mouth with table intentions that had about 5 inches of leader projecting from it butt. Upon cleaning, it was attached to a hook that was about 2 inches short of making it through the large intestine and out the butt hole. The intestine was perforated by the hook and the hook looked to be rusted and an estimated 50% of its original mass. The fish was quite healthy though.

I've landed several other fish over the years that were packing hooks in some portion of their jaws, but nothing else that had one work it's way through the digestive system. I've not looked for any peer reviewed literature on hooks decomposing, but one would think there might be some real data out there somewhere.

In my younger bait days I'd simply cut the line and let the fish have the hook. Now I've pretty much gone the fly route and a swallow is an extreme rarity.

Here's a little info although it's not a peer reviewed article Pike and lures link

and a second link with a little duplication (Hooks and strippers link

and a third summary (A third summary link)

With today's animal welfare mandates, I suspect it's becoming quite difficult to conduct such studies.

Last edited by 1minute; 09/23/18.
1Minute