ST. PAUL — The Department of Natural Resources issued Tuesday the beginnings of a plan to boost Mille Lacs Lake’s declining walleye population, starting with studies that could lead to tighter regulations for one of Minnesota’s most popular fisheries.

The DNR said it plans to convene a panel of experts to review past and current management practices. It also plans to contract out for a review of how it conducts fish population estimates. And it plans a new study to determine how predator fish such as northern pike and smallmouth bass affect the survival of young walleyes.

DNR fisheries chief Don Pereira said a key problem is the vast majority of Mille Lacs’ walleyes don’t survive to their second autumn. While the lake’s older, spawning walleyes produce more than enough eggs and fry to repopulate the lake, he said, the lake hasn’t produced a strong year-class of walleye since 2008.

The announcement did not include changes to bag or size limits. Pereira said those will come after fisheries officials determine the “suite of regulations” necessary to get the lake back on track. Some walleye rule changes could come this spring, he said, though he’d prefer to stick with current regulations for the upcoming season.

Pereira acknowledged that current management practices have contributed to the decline. He said they were based on the best available information in the 1990s, after the courts ruled that Ojibwe bands still had treaty rights on the lake and before the arrival of harmful invasive species and declines in forage species. He said current practices have depleted too many walleyes between 15 and 18 inches. He said managers now know mortality should be spread over a broader size range.