Is there evidence to suggest that holding a big lake trout, muskie, pike, or catfish by its jaw or gill plate, without supporting its belly, can be injurious? Rob Swainson, who manages Ontario's Lake Nipigon and Nipigon River, says anglers need to handle big trout differently than small ones. Swainson remembers landing his first big trout. He gloved it by the tail and lifted it out of the water--that's when he heard a popping sound--as the vertebrae separated in the fish's backbone.

If holding a heavy fish vertically by its gill plate, without supporting its belly, can result in damage, why do we catch so few fish with obvious injuries? Swainson says he's only seen one or two large lake trout with deformed backbones. "I'm not surprised," he says, "because popping vertebrae likely means death for big fish. They swim away, but I doubt they survive.

"Big fish need extra body support," he says. "If someone were to lift you up," he asks rhetorically, "would you want to be held by the neck? Or would you rather be lifted by putting both arms under your body?"

As an assistant hatchery supervisor, Ohio biologist Elmer Heyob sees more fish with deformed backbones than most field biologists see. Most of the fish he sees with crooked spines are survivors of genetic defects. You don't see them in the wild, he notes, because they never make it past the fry stage.

Like Swainson, Heyob is an avid angler, with muskies a particular passion. He says one problem with holding a big fish vertically is that the fish appears to calm down. Heyob says the fish are calm only because they're nearly paralyzed from vertebrae strain.

Heyob: "We have an Ohio-based muskie club annual tournament that Ohio Division of Wildlife personnel often attend. We keep a redwood measuring board handy that we also use in our research. One of the contestants caught a muskie that they hung from a hook at the marina. When they measured it with a tape it was 51 inches long. When we remeasured it on the board it had shrunk back to 49 inches." The extra length was from vertebrae separation.

If you must measure a fish, Heyob and Swainson recommend doing it while the fish is in the water alongside the boat. "In a perfect world," Heyob says, "we'd just look at the fish in the water and remove the hooks. But many anglers want a picture or two and sometimes the actual weight of a big fish."

When lifting a large fish out of water, it's essential to support most of its weight with one hand under the belly. It's the same for using one of the new tools that grips a fish's mouth and contains a built-in scale. A more fish-friendly weighing method, according to Heyob, is to lift the fish in a knotless net turned on its side, using the gripping tool to hang onto the hoop to get the weight (subtract the net weight).