They lived through the fall of the dinosaurs and were there as the Great Lakes formed, surviving as a species relatively unchanged for some 200 million years. But the life of the sturgeon of North America may be nearing its end.

Over the past century, lake sturgeon have lost more than 99% of their population and have been wiped out of more than half of their native spawning grounds. In response, the U.S. Fish and Wildlife Service (FWS) announced last week it will study whether to list the fish as an endangered or threatened species, clearing the first hurdle to provide federal protections for sturgeon in Minnesota and the Great Lakes states.

The decision could set up one of the first tests of the Trump administration’s rule changes to the Endangered Species Act, which were announced Monday.

“This is long overdue and such a long time coming,” said Jeff Miller, senior conservation advocate at the Center for Biological Diversity, a conservation group fighting to expand protections for sturgeon. “The only way to describe the decline of the sturgeon is catastrophic.”

Lake sturgeon would become the 20th endangered or threatened species in Minnesota if they are listed, joining the gray wolf, Canada lynx and rusty patched bumblebee, among others.

The Endangered Species Act has proved to be the country’s most effective tool for saving individual species since it was signed in 1973. It’s largely credited with bringing bald eagles and peregrine falcons — the world’s fastest living creatures — back from the brink of extinction after they were nearly wiped out by the farming pesticide DDT. The protections have helped re­introduce wolves to the Upper Midwest and have kept a number of species that are still struggling, such as whooping cranes, from disappearing.

They’re also a major reason trumpeter swans and osprey are still seen in Minnesota, said Keith Olstad, president of the Audubon Society’s Minneapolis chapter.

The Trump administration’s rule changes will make similar recoveries harder to accomplish and more unlikely, Olstad said.

“There’s this attitude as though we can live independent of the environment, but we can’t,” he said. “We’ll all be much poorer for the loss of species.”

Jurassic-era survivors

Sturgeon, armor-plated throwbacks to the Jurassic era, have been able to survive just about everything the globe has thrown at them.

But throughout the 1900s, sturgeon populations were decimated by overfishing from commercial fisheries during spawning runs and by dams and other man-made barriers that cut adult sturgeon off from their spawning grounds, according to the petition for protection filed by the Center for Biological Diversity.

While sturgeon haven’t been fished in any significant numbers for decades, populations have never really rebounded. That’s partly because the fish, which live for more than 100 years and grow to up to 300 pounds, don’t start reproducing until they’re 15 to 25 years old, Miller said. Even then, they don’t reproduce every year.

“It’s such a long time scale that you’re talking decades for them to get back,” he said.

They have also lost ground as invasive species, such as carp, move in and as pollution, dredging and drainage projects destroy their habitat.

There were once an estimated 15 million sturgeon in the Great Lakes alone, but there are now just six areas in the U.S. with populations of more than 1,000 adults, according to the petition.

Still, sturgeon have been doing relatively well over the past two decades in parts of Minnesota, especially north along the Rainy River. Habitat restoration efforts led by the Minnesota Department of Natural Resources and Pollution Control Agency, stocking programs and, especially, the removal of obsolete dams have helped sturgeon numbers stabilize and start to recover.

Both Minnesota and Wisconsin allow limited sturgeon fishing seasons. Minnesota anglers can keep one a year.

In its preliminary review, the Fish and Wildlife Service found that every state still home to sturgeon has created some form of conservation program, but there was “substantial” evidence that existing regulations may be inadequate to deal with the combined threats the species faces.

The FWS will begin a yearlong review before making a decision on the sturgeon. The agency could either declare the fish threatened — one step below endangered — throughout the U.S. or decide whether to list it as either threatened or endangered by each distinct population.

If sturgeon are listed as threatened, it’s unclear what it would mean for Minnesota’s fishing season.

Changing the rules

Since the late 1970s, every threatened species has automatically received all the federal protections of an endangered species, including strict habitat protections and a ban on harvesting. But under new rules announced Monday by the Department of the Interior, regulators will determine each type of protection for a threatened species on a case-by-case basis.

The rules also limit consideration of threats to the “foreseeable” future, which conservation groups say allows the administration to ignore big-picture issues such as climate change and invasive species.

Interior Department officials said in a statement that the changes will ease regulatory burdens and increase transparency without sacrificing recovery goals. The changes would go into effect next month if they survive expected court challenges.

The new rules would only ease federal protections in Minnesota.

The Minnesota DNR keeps its own list of endangered and threatened species that includes nearly 300 plants and animals. Those protections will not change, said Rich Baker, DNR endangered species coordinator.

Minnesota’s list, notably, does not include either the gray wolf or the lake sturgeon. The federal listings take into account populations — and their decline — on a more global scale, but Minnesota’s list only looks at how the species is doing inside state boundaries, Baker said.

“The state has been doing a lot to try to benefit sturgeon,” he said.

Threats facing species throughout the state are increasing, Baker said, pointing to a recent United Nations report that found 1 million species at risk of extinction.

“That’s not hyperbole,” he said. “Whether you’re talking about climate change or habitat loss due to development and the use of chemicals and pollutants, this is not a great time for endangered species.”