Mack Days expands to 51 days this year

The Spring Mack Days fishing tournament is just around the corner, and organizers are looking for the event to remove about 9,000 more lake trout from Flathead Lake than in last year’s event.

Begun in 2002, the Mack Days fishing tournament is sponsored by the Confederated Salish and Kootenai Tribes and sanctioned by Montana Fish, Wildlife and Parks. The tournament is part of the Tribes’ ongoing efforts to reduce the number of non-native lake trout in Flathead Lake and hopefully bolster populations of native fish, such as the bull trout. The annual spring event is held March 20 through May 17. There is also a Mack Days in the fall.

Flathead Lake had been jointly managed for 10 years by the Tribes and FWP until 2010, when their co-management plan ended. The Tribes decided on their own to pursue gill netting of lake trout, a plan the state opposed. The Tribes currently manage the south end of Flathead Lake, and the state manages the north end.

Last spring, Mack Days competitors removed about 31,000 lake trout from Flathead Lake. Combined with the Tribes’ first season of gillnetting and the fall Mack Days event, about 77,000 lake trout were removed from the lake in 2014, CSKT fisheries biologist Barry Hansen said.

The Tribes monitor the lake trout population largely through tagging. Hansen said that number is still too low to make the kind of impact they want to see in reducing lake trout in Flathead Lake.

“Lake trout have been pretty much at a level where they largely self regulate,” Hansen said. “They have a large critical mass that they can sustain and there’s a certain level of harvest that’s sustainable. That’s the tipping point we need to reach.”

To increase the numbers of fish harvested in Mack Days this year, derby managers have added weekday competition. That will provide anglers 51 days to catch a tagged fish worth more than $10,000 or to increase their winnings by catching more than 1,200 fish.

“So many people work during the week, we want this to be as fair as possible,” Mack Days technician Cindy Benson said.

For every fish an angler catches, a fisherman receives one ticket for the season-end lottery. Once an angler reaches a certain number of fish, they are paid a bonus. Up to $225,000 in cash and prizes will be awarded.

Hansen said gillnetting was added to the Tribes’ management efforts because the tournaments were not reducing enough lake trout.

“It has confirmed that the harvest to date hasn’t really been able to affect population size,” Hansen said. “That’s exactly why we initiated gillnetting, because we just couldn’t get that crucial harvest with angling alone.”

Fish that are caught by Mack Days competitors are processed and donated to local food banks.

Last year, tribal biologists aimed to remove 90,000 lake trout from Flathead Lake with two seasons of gillnetting and spring and fall Mack Days, but they fell short by about 13,000 fish. This year, they would like to harvest 98,000 lake trout.

“To get there, we have to expand the efforts that we’ve done in the past,” Hansen said. “One good way to do that is expand and modify the Mack Days contest. So we thought this year we would expand to weekdays.”

In addition to expanding Mack Days, the Tribes also plan to gillnet for eight weeks in the spring, compared to two weeks last year.

“We’re slowly building the program,” Hansen said.

Tribal biologists are also learning how to narrow down their gillnet catch only lake trout. The first year of gillnetting, they removed about 8,000 lake trout with only one bull trout casualty, Hansen said.

“Our intent is to maintain that kind of ratio,” he said. “Lake trout are a serious predator on bull trout, and we’ve got to reduce their numbers to benefit bull trout.”

The Tribes started spring gillnetting last week and will wrap up in May, depending on the weather. They’ll be netting during the derby, as well as tagging more fish for anglers to catch.

While tagging fish is primarily a way for biologists to track populations, tagged fish caught in the Mack Days contest are often worth cash prizes ranging from $100 to $10,000. More fish will be tagged before the event begins, and tagging will continue throughout the event.

For more information about spring Mack Days, gillnetting and the lake trout suppression effort, visit online at www.mackdays.com.