TRAVERSE CITY, Mich. — Federal regulators said Wednesday they will consider extending legal protections to lake sturgeon — prehistoric fish once abundant in the Great Lakes but reduced to dangerously low numbers by overfishing, pollution and habitat destruction.

The U.S. Fish and Wildlife Service said an initial review had yielded “substantial information” on continuing threats to the sturgeon, justifying a more detailed study of whether they should be listed under the Endangered Species Act.

Designating the sturgeon as endangered or threatened could boost efforts to open more spawning areas, said Jessica Collier, a fish biologist with the service based in Green Bay, Wisconsin.