'Hooking mortality' count one more Mille Lacs sore point

Garrison, Minn. – Drive 60 miles away from Lake Mille Lacs in any direction and you'll get a lot of blank stares from people when you ask them why "hooking mortality" is such a big deal.

But within the Mille Lacs community, the issue could fuel its own daily talk show this time of year as the Department of Natural Resources (DNR) prepares to set summer walleye regulations that hinge on a limited allocation of fish.

For two years in a row now, Mille Lacs anglers have killed more walleyes in the process of catching and releasing them than they have by catching them for keeps. Both forms of death count against the allocation, and an unexpected surge in hooking mortality last July pushed Mille Lacs past its seasonal walleye limit and prompted a shocking, midseason shutdown of walleye fishing.

"We can't have another shutdown," said Steve Johnson of Portside Bait & Tackle near Isle.

Johnson is one of several Mille Lacs area business owners on the DNR's Mille Lacs Fisheries Advisory Committee who believe the DNR is overestimating hooking mortality. The 17-member group was formed in October out of the growing crisis over the lake's changing biology and stunted walleye population. At a heated meeting last week, community members asked for changes.

"There's legitimate questions about the model and the data that go into it," Johnson said in an interview.

Tom Jones, the DNR's regional treaty coordinator, said the agency has demonstrated the current methods are "basically sound." Yet the concerns about possible inaccuracy are now under review and could bring changes. "We've made a new computer model, but we haven't vetted it yet," he said.

Still, discussions on how to reduce hooking mortality are in vogue around the lake. In 2015, a whopping 64 percent of the season's walleye allocation was reached via hooking mortality. In 2014, the breakdown of walleye deaths was 54 percent from hooking mortality.

"Hooking mortality has started to exceed harvest," Jones said.

One important factor in the trend is the lake's stringent bag limit (only one 18- to 20-inch walleye per angler could be in possession last year). That normally requires anglers to catch and release a lot of other fish until they land a keeper. A percentage of those released fish die depending on water temperature and length of the walleye.

The warmer the water, the higher the hooking mortality. In addition, small fish and extra large fish are more likely to die than mid-sized fish.

The worst-case scenario for hooking mortality is for lots of too-small or too-large fish biting hooks in hot weather. That's what happened last year when the catch rate soared six times higher than expected in July.

"If people could keep one of those, they wouldn't have to catch and release 100 or 150 of them,"Johnson said.

Final regulations for 2016 won't be decided until early March, but DNR fisheries chief Don Pereira said at Tuesday's meeting that the lake needs "spawners." The key problem on Mille Lacs is that too few baby fish are surviving until their third autumn. "We are in a precarious position," Pereira said.

Karen McQuoid, a biostatistician from the medical device industry who also operates Mac's Twin Bay Resort, said the DNR's hooking mortality model, created in 2003 and '04, is flawed. For one thing, the model assumes all Mille Lacs walleye are caught similarly, with live bait. The model doesn't take into account sharply lower mortality rates associated with fish caught on artificial lures, McQuoid said.

Jones said he doubts methods have changed enough to make much of a difference in the overall mortality of released fish. But he said it's possible to start tracking how people are catching walleyes and incorporate the data.

Jones also said the DNR is considering shifting to a new method of data collection for water temperature. New readings would come from a recording thermometer submerged 6 feet below the surface, away from shore. Those readings might be mildly cooler, meaning fewer deaths in released walleyes.