When a walleye is caught in Minnesota, it's either kept and eaten -- or released. Most that are set free live to fight another day.

But some don't.

At Lake Mille Lacs, the number of released walleyes that die is crucial because they are included in the state's allocation under its agreement with eight Chippewa bands. Last year, sport anglers "harvested" 310,000 pounds of walleyes. But an estimated 136,000 of those pounds were fish lost to hooking mortality -- ones that didn't end up in a freezer or frying pan, but nonetheless were counted against the state's allocation.

In past years, that was an unfortunate but mostly inconsequential byproduct of fishing regulations that required anglers to release large numbers of fish that were outset their permitted harvest "slot."

Now it's a big deal.

Concerned about the lake's declining walleye population, state officials have slashed its 2013 walleye allocation to 178,750 pounds -- half of last year's allotment. The bands' quota also was cut in half, from 142,500 pounds to 71,250.

The problem for anglers: If hooking mortality is 130,000 pounds again this year, and winter anglers keep 20,000 pounds, as expected, that would leave sport anglers only 29,000 pounds of walleyes in their yearly allotment, beginning with the open-water fishing season.

It would take Draconian fishing regulations -- maybe even catch-and-release only -- to prevent overharvest.

"We're trying to avoid that," said Tom Jones, Department of Natural Resources large lake specialist for Mille Lacs. "We need to figure out a way to convert that hooking mortality to harvest. But that's a trick. We can't go over our 178,000-pound allocation."

Options are few

Fishing guide Tony Roach is on Mille Lacs 200 days a year. He said hooking mortality could be reduced if anglers were to properly release fish.

"Some have no idea how to pull a hook out; some don't know you're supposed to cut the line on a deeply hooked fish," he said. "I've seen people taking pictures of fish for 10 minutes. The fish are out of the water way too long, and they are allowed to flop around on the ice or the bottom of the boat."

He suggested a barbless hook requirement could reduce mortality.

"I wouldn't be opposed to that," he said.

But Jones said studies have shown that barbless hooks won't significantly reduce mortality.

"They might reduce mortality on small fish, but not on big fish," he said.

Restricting the use of live bait is another idea that's been floated. It might not directly reduce mortality, but perhaps would reduce fishing pressure.

Also, "If you required a jig instead of a regular hook, there likely would be fewer incidents of deep hooking," Jones said.

Terry Thurmer of Terry's Boat Harbor on Mille Lacs agrees some anglers do a poor job of releasing fish.

"The only way to reduce mortality is to keep bigger fish, the ones we're throwing back," he said.

Both Roach and Thurmer worry that whatever regulations are imposed on anglers by the DNR for the coming season, businesses around the lake will be hurt.

Roach says he'll survive if Mille Lacs essentially becomes a catch-and-release fishery, because many of his customers are content to catch and release. Still, others want a walleye dinner.

"I've been here going on 24 years, I'll survive," Thurmer said. "But anyone who just bought a resort, they're not going to survive."

Mortality studies

The DNR's fish mortality estimates for Mille Lacs are based on studies the agency did on the lake a dozen years ago, when fish caught with hook and line were placed in holding pens in the lake to see how many died.

"We found hooking mortality depended on water temperature and size of fish," Jones said. "Really small fish and big fish have higher mortality rates."

One surprise: "We put fish in that were belly-up, that we were sure were going to die, and they survived," he said.

Jones said there wasn't a huge difference in mortality between fish caught on artificial lures and hooks.

DNR officials are still exploring regulation options, and will offer those to the Lake Mille Lacs Input Group, a consortium of resort owners, bait shops and other businesses, at a meeting next month.

But there are no easy answers.

"Even if it's a total catch-and- release fishery, it's possible we would still go over the quota," said Don Pereira, DNR fisheries research manager.

"We are in a pickle," Jones agreed. "Whatever we come up with, people aren't going to like."

Doug Smith • dsmith@startribune.com Twitter: @dougsmithstrib