The story is basically the same everywhere it's told. Once some maintenance or construction divers were working on (insert local dam or bridge here) when they saw catfish swimming along the base of the dam that were literally large enough to "swallow a man whole." One account I read about occured on Lake Martin in Alabama, and the diver at first mistook the catfish, which was lying on the bottom of the lake, for a submerged tanker truck. He walked the length of the fish, and found what he thought was a flange on the tank, only to discover that it was the eye of the fish.
Some of the stories have a strong apocryphal element to them. Children are warned not to swim out too far or the catfish will "get them".
Is there any truth to the stories? Has any researcher contacted any scuba divers or the Army Corp of Engineers to get to the truth? How are the dams and bridges maintained if nobody will dive there? I would imagine that scuba-qualified construction workers or engineers are a pretty small, closely-knit community, and word would spread pretty fast among them, right? Are new, fresh recruits who've never heard the story contracted out?
Why does the giant catfish story persist? It's easy. Catfish DO get big. Bigger than most non-fishermen would imagine. Years ago, I worked as the night manager at a nearby truck stop. In the early, predawn hours one Sunday morning, a man came strolling in and asked if anyone wanted to see a big catfish. A few of us went outside to check it out. As we approached the truck (one of those import "mini-trucks" that were popular at the time) we could see the top of the fish's back over the side of the bed. The fish was so long that it was too long for the (admittedly small) truck bed, and had about two feet folded around. I'd estimate its length to have been at least 6 feet.
In the early 90's, our local paper (The Decatur Daily, Decatur AL) ran a story of a catfish that weighed over 100 lbs caught in the Tennessee River. (I don't remember the exact weight, 104 and 108 stick in my mind for some reason). The angler wrestled with the fish and finally managed to reel it into shallow water, at which point some observers waded out and attached a rope to it and pulled it ashore. Because the fish wasn't landed with a fishing pole, it wasn't eligable for record consideration, despite its "record" size and weight.
Anybody who knows catfish will tell you that about all catfish do is swim and eat. They poke along the bottom, using the taste receptors in their whiskers (and in some species, even their skin) to find anything that tastes appealing. One would imagine that in the deep water at the base of a dam, there's plenty to eat, so they just eat and grow. (I know another story about a coroner's assistant who will never eat catfish again, but that's a different matter!)
So, people have seen big catfish, the base of a dam seems to provide the ideal environment to produce giant catfish, ergo, the whole story seems to make perfect sense.
In Part 2 I'll discuss my frustrations with my plans to try to catch one of these monsters.