A host of Minnesota's lesser-known fish may get their first protections from over-fishing and will no longer be lumped in with invasive species under state law as something little better than a throwaway catch.

The state Department of Natural Resources (DNR) this week gave lawmakers recommendations on how to better protect and understand 23 native species that have been considered "rough fish" by Minnesota fishery managers for more than a century.

Some of those species are struggling. The population of white suckers may have fallen by as much as half since the 1970s. Others, including the freshwater drum, are among the only creatures in Minnesota's waters that will eat invasive zebra mussels, which are infesting lakes throughout the state. Two other little understood fish on the list — goldeye and mooneye — were discovered in recent years to be the singular key to saving one of the most endangered animals in the state.

Taking rough fish has largely been unregulated, allowing anyone to kill unlimited numbers of them, whether the fish are eaten or not. The state prohibits "wanton waste" — killing animals merely for sport. As long as the dead fish are used for something like fertilizer, they can be taken.

The wanton waste rules have come under scrutiny after videos surfaced of people killing hundreds of gar, suckers and bowfin at a time. The DNR said it will reconsider whether fertilizer is an appropriate use for native fish.

The DNR also asked lawmakers to expedite the rule-making process to allow the agency to quickly set bag limits and fishing seasons for any of the native species it deems necessary. The DNR found 70 uses of rough fish that would must be changed in 22 state laws to differentiate the native fish from invasive ones, such as common, grass and bighead carp that the state is actively trying to eliminate.

Those three actions would be steps in the right direction, said Tyler Winter, a spokesman for the Izaak Walton League of America, which advocates for Minnesota's native nongame fish.

"Not providing basic regulations or minimal protections like enforcing wanton waste is insanity," Winter said.

For too long these species were managed as unwelcome competition to walleye, crappie or other game fish, he said. Kill a pound of gar and a pound of walleye will move in, the thought went. But over the decades, scientists have learned how wrong that reasoning was and how vital these fish are to popular and unpopular fish alike.

Each species evolved to fill a niche in Minnesota's waters. Many are important prey. Goldeye and mooneye are the only known host for juvenile spectaclecase mussels — the highly endangered bivalves can't reproduce without them.

Far more studies are needed to learn about population trends as well as habitat and spawning needs for the 23 species, the DNR wrote. Some research has started, but priority studies should be made for bowfin, gar, redhorses and buffalo fish.

Habitat restorations and dam removals will likely also be critical to stabilizing any fish populations in decline, the agency said.

Any bag limits that the DNR sets for some of the species will help, said Steve Herrington, associate director of water for the Nature Conservancy in Minnesota.

"This is only going to help show the intrinsic value of these native fish," he said. "Just look at bigmouth buffalo: They live for over 100 years and migrate hundreds of miles to spawn. They should be elevated to something of equal importance with sport fish, with the walleyes of the world."

Lawmakers ordered the DNR to come up with the recommendations last year. The Legislature's next session begins in February.