When the ice finally goes off Mille Lacs, the big lake will be a busy place. Thousands of anglers will be among those seeking walleyes when the lake opens, together with Chippewa netters and spearers and Department of Natural Resources fisheries survey crews.

It's unlikely the lake will be entirely free of ice when sport fishing begins May 11, though some open water is evident now at creek mouths and along certain shorelines — indicating that near-shore fishing might be possible in spots.

Some Chippewa band members already are harvesting Mille Lacs fish. Northern pike spearing is happening at some creek mouths, and limited under-ice walleye netting has occurred. As of last week, 119 pounds of walleyes were reported in the tribal harvest, and 46 pounds of northern pike.

When Mille Lacs finally is ice-free, extra DNR enforcement officers will be assigned to the lake to ensure anglers' limits are enforced, and to be alert for possible conflicts between Chippewa netters and sport fishermen.

Invasive species transport laws also will be a priority, according to DNR regional enforcement supervisor Ken Soring of Grand Rapids.

Mille Lacs is receiving heightened attention this year in part because recent surveys indicate the lake's walleyes are at a 40-year low.

Most years, the tribal harvest is complete before hook-and-line fishing begins. But the late spring this year means the two factions likely will be on the lake together, at least for a period of days. DNR fisheries survey crews also will be in some of the same shoreline areas where tribal and sport anglers gather.

"But we don't plan to have our crews on the lake opening weekend," DNR area fisheries supervisor Rick Bruesewitz said, acknowledging that ice might make that effort impossible.

The Chippewa also have no plans to be on the lake opening weekend, Soring said.

This year's spawning run on Mille Lacs and most other northern Minnesota lakes probably will happen in a hurry. Timing of the spawn is determined by day length and water temperature. Once lakes are ice-free and the water warms to 40 degrees or so, males and females will enter and leave the spawning grounds relatively quickly.

Unknown is how many members of the eight Chippewa bands — six from Wisconsin — that harvest Mille Lacs will spear instead of net this year. The bands have been asked by the Great Lakes Indian Fish and Wildlife Commission (GLIFWC) to consider increasing their spearing effort because biologists worry too few small walleyes inhabit Mille Lacs.

Band members who spear could select larger fish to harvest, while gill nets the bands employ typically target smaller walleyes.

"We keep track of the lake, and when there are open spaces along shore, we'll be ready to go," GLIFWC tribal spokeswoman Sue Erickson said. "We're hoping more band members take [Mille Lacs] walleyes this year by spearing. We don't know how many will. But most members from Wisconsin who travel to Mille Lacs are experienced spearers."

In Wisconsin's ceded territory, where Chippewa harvest fish off their reservations, spearing is the preferred tribal fishing method, Erickson said.

It's also possible on Mille Lacs this spring that sport anglers might inadvertently cut or otherwise interfere with band nets. Net buoys at times can be difficult to see, particularly in rough water, and shoreline areas where walleyes congregate likely will be congested with boats.

"[Band members] will have to be prepared to watch their nets," Erickson said.

Meanwhile, DNR crews will attempt to catch and tag about 20,000 Mille Lacs walleyes during the spawn. Some fish will be stunned momentarily by electric shocks sent into the water, then tagged when they float to the surface. Others will be caught in hoop nets — a kind of live trap that allows for easy catch-tag-and-release.

Weeks later, when the tagged fish have dispersed throughout the lake, DNR crews will be on the water again, this time using gill nets to capture walleyes. The ratio of tagged to untagged fish caught in this second effort will help determine the lake's walleye population.

Mille Lacs anglers are limited to two walleyes this year between 18 and 20 inches (or, one can be a trophy over 28 inches). In 2012, the limit was four under 17 inches (with one trophy), a size that proved difficult to find.

Cut in half from a year ago, the 2013 Mille Lacs walleye sport-fishing quota is 178,500. The tribal quota was similarly sliced, to 71,250 pounds.