DULUTH, Minn. — Biologists have found evidence that sturgeon are spawning successfully in the St. Louis River, marking only the second time that recently hatched sturgeon have been found there.

Fishery biologists with the Fond du Lac Band found a single tiny sturgeon last week that hatched from an egg, the Duluth News Tribune reported (http://bit.ly/11ycNf8 ). The only other time that happened was in 2011, when the same team of biologists found four tiny fish.

The find is important because it suggests consistency in the sturgeons' natural reproduction, said John Lindgren, a fisheries specialist with the Minnesota Department of Natural Resources.

Overfishing and pollution had taken a toll on the sturgeon, which are prehistoric-looking fish that can live 100 years or more and weigh more than 100 pounds. The Minnesota and Wisconsin departments of natural resources began stocking the river with sturgeon in 1983 but stopped in 2000 to see if the fish would reproduce on their own.

Last week's discovery suggests so.

"It means we're getting consistent natural reproduction," Lindgren said. It's unclear whether there was natural reproduction last year because flooding made it difficult to take samples, but Lindgren assumes there was.

The tiny sturgeon that was found last week was less than an inch long, said Brian Borkholder, fisheries biologist with the Fond du Lac Band.

"It had a big, triangular, very sturgeon-looking head and a long, thin tail," he said.