The chief executive of the Mille Lacs Band of Ojibwe has notified all band members that treaty rights lawyers are considering legal action to counter Gov. Mark Dayton’s decision last week to keep walleye fishing open on Lake Mille Lacs.

Melanie Benjamin, Mille Lacs Band chief executive, hasn’t elaborated on the open letter posted to her Facebook page. The letter says lawyers are working “to determine our best legal options to protect the lake and our rights.’’

On Tuesday, the group representing the Mille Lacs band and seven other Chippewa bands with federal treaty rights confirmed that potential litigation is being studied.

“From here on out, I’m not sure what the next move is,’’ said Dylan Jennings, spokesman for the Great Lakes Indian Fish & Wildlife Commission. “The bands are most concerned about the longevity of the resource.’’

At issue is Dayton’s move last week to break this year’s joint management agreement governing the annual walleye harvest by band members and state-licensed anglers. The co-management system is court-ordered, and this year’s state allocation was 28,600 pounds. The Department of Natural Resources announced last week that the quota was surpassed based on hooking mortality estimates from a season-long catch-and-release restriction.

But rather than shut down the lake, as the DNR did last year, Dayton decided to allow catch-and-release fishing to continue in 2016 for socio-economic reasons. DNR officials said the move won’t hurt the ailing fishery.

Susan Klapel, the Mille Lacs Band commissioner of Natural Resources and Environment, said Tuesday that she’s concerned the overharvest will be negative for the biological future of the lake’s walleye population.

“While the impacts on walleye are yet to be determined, the impact on the relationship between tribes and the state of Minnesota is clear — it damages our ability to trust the state of Minnesota to keep its word in negotiations, and to co-manage the lake based on sound science,’’ Klapel said.

In her letter, Benjamin said that Minnesota has disregarded the federal court order on co-management. “What happens next will be determined collectively by us and all the impacted bands.’’

She contrasted Minnesota’s willingness to surpass its walleye allocation to under-allocation and restraint by the Chippewa. This year’s walleye harvest quota for tribal fishing was set at 11,400 pounds. “As requested by our Drum Keepers and Elders, all the Bands have sacrificed greatly in taking much less than our communities need,’’ Benjamin wrote.

She added: “As has been our history, the Band has kept our promise. But in violation of the court order, the promise was broken on the other side. We will do whatever we must to ensure the ogaa [walleyes] are protected for generations to come.’’

She closed: “Someone needs to protect the lake. The Mille Lacs Band will certainly do so. I know that we can count on the other Bands to stand with us, even if the state chooses not to. As with our treaties and our other rights, the Band will fight for justice, for our rights and for our future.’’