PESHTIGO, Wis. (AP) - Man's infringement and native species have changed the Great Lakes forever, but two tributaries of Lake Michigan will soon harbor their prehistoric inhabitants.

The Michigan Department of Natural Resources is reintroducing sturgeon to the Cedar and West Branch Whitefish rivers. In a joint project with the Wisconsin DNR and Wisconsin Public Service Corp., eggs were collected from four sturgeon in the Peshtigo River May 5.

The eggs were transported to portable hatcheries on the two rivers.

They were fertilized from the milt of 17 males caught on the Peshtigo.

The sturgeon began hatching about 10 days later. The sturgeon fry will remain in the safe haven of the hatcheries until September, when they will be stocked into the rivers.

"We're hoping we can stock about 1,500 fish per river," said Ed Baker, fish biologist with the Michigan DNR in Marquette. "Sturgeon survival rate in the wild is pretty high compared with other fish."

When released into the two Upper Peninsula rivers, the sturgeon will be about 4 to 6 inches. The first year is the most critical. Soon, they will be too big for predator fish.

"We think about half of them will survive," Baker said.

The Cedar and Whitefish rivers in the U.P. had sturgeon populations before European settlers arrived. The DNR surveyed both rivers and found no remaining sturgeon populations.

"The habitat is still in good shape," according to Baker.

Each river has one barrier - a dam on the Cedar and a lamprey barrier on the Whitefish.

Baker said it's not inaccurate to say the health of the Great Lakes ecosystem is not what it used to be, but this project is one step in the right direction.

"There have been tremendous changes to the fish community and ecology of the Great Lakes. By reintroducing native species we're trying to restore some of that eco health," Baker said.

Collecting sturgeon eggs was no easy feat. WPS agreed to lower water levels on the Peshtigo. A crew of 10 fish biologists from both state agencies gathered on a small island just below the Badger Paper Dam.

In a scene out of a "Jaws" movie, numerous sturgeon fins jutted out of the water and their sharklike tails whipped through the clear, shallow, rocky water as they gathered near the island for their annual spawning ritual.

One by one, 65 sturgeon were netted, measured, weighed and inspected for tags and health condition. A tissue sample was taken from each for genetic analysis at Michigan State University. An internal tag was injected into each fish via a hypodermic needle. That will allow fish biologists to identify fish if they're captured again.

Out of the 65 fish, just 12 had been captured previously. That's a good sign, according to Mike Donofrio, Green Bay fisheries supervisor.

"If recapture rates are high, that means there is a small population," Donofrio said. "Over the years we've seen more fish return to the Peshtigo River, so we are very encouraged."

Sturgeon fishing is allowed on the Menominee each September, but there is no sturgeon season on the Peshtigo. If the population there continues to improve, it's possible the Peshtigo could someday be opened to sturgeon fishing, Donofrio said.

He estimates the spawning population of sturgeon in the Peshtigo at 500. The Lower Menominee River below the Hattie Street Dam has a spawning population of about 1,000 sturgeon, he said. There are thousands more in the middle and upper stretches of the Menominee. In both rivers, it is not a resident population of sturgeon because they return to Green Bay after spawning.

Among the 65 sturgeon caught on the Peshtigo were a 101-pound, 72-inch male and a 98.5-pound, 73.5-inch female bursting with eggs. Just 10 of the fish were females.

One of the fish still had an antenna sticking out of its belly. In 1996, the DNR implanted sturgeon in the Menominee River with antenna to track their seasonal movements.

Donofrio was surprised to see a sturgeon still swimming around with an antenna years later.

"It's pretty amazing that fish has been swimming around with that antenna since 1996," he said.

WPS reduced the flow through its hydroelectric dam on the Peshtigo May 5.

"It was not a big inconvenience for us at all," said Jenny Short, WPS community relations leader.

Donofrio said that by closing most of its gates, WPS lowered the water level by a foot or two - enough to help catch and release the sturgeon.

"That wouldn't have been possible without WPS cooperation," according to Donofrio. "They were a big help. From the moment we asked if they would cooperate, they said 'No problem at all.'"

Collecting spawning sturgeon on the much deeper, darker Lower Menominee would have been much more difficult, Baker said.

Male sturgeon reach sexual maturity at about age 15, while females don't begin reproducing until they're about 20 years old.

Future generations are bound to experience naturally reproducing sturgeon populations on the Cedar and West Branch Whitefish rivers.

"People have referred to sturgeon as the bald eagle of the Great Lakes," Baker said. "They're equally important to the ecosystem as bald eagles and the gray wolf."