Let me relate a fish story from my yout:
I was a teenager with three ponds available to me to fish any time. I had gone to the pond closest to home and found the bass were on bed. Catch and release had not become popular back then and being able to see dinner ahead of time was rather exciting. I settled in on a bass I saw which probably weighed a little over 3 pounds and began to harrass her. After a few hours she finally became irritated enough to strike. I got her in and was more than a little excited. I put her on my stringer and dropped her in the water. As soon as she hit the water she took off taking my stringer with her as I had not stuck the metal end in the ground yet. I was very frustrated and had only one stringer so I packed up my gear and went home.
A few days later I was back at the pond. This time I was flyfishing. As I approached a laydown in the water I noticed a fish hitting the surface. I flipped my fly to it. No response to my fly. I inched closer. Again laid my fly near the swirl no reaction. After a while I began to notice a twig bobbing with every thrash by the fish. I got closer to get a better look. Sure enough there was the bass from a few days before. She had gotten the stringer tangled in the laydown. I crawled out on the tree and succeeded in wrapping my flyline around the limb several times and pulled it to me. I retreived my stringer and the fish. She was worse for the wear. I took the fish home but my mom thought better of trying to eat her.
I learned a valueable lesson about making sure your stringer is secure before returning a fish to the water.