Can the sturgeon make a comeback in Florida?
Scientists wonder if the fish can be revived in state waterways.

Decades after one of the planet’s oldest fish vanished from the St. Marys River, scientists are wondering whether they can bring it back.

The Atlantic sturgeon, a jumping, armored fish that can grow up to 14 feet long, has dwindled along the East Coast to the point that federal agencies are considering labeling it an endangered species.

Thought to have once lived in the St. Johns River, the fish hasn’t been seen there in generations and has lost territory from the Southeast to New England.

But the deep, winding St. Marys on the state border intrigued government scientists who thought its mostly undeveloped reaches might be a place to rebuild a population shrunken by water pollution and commercial fishing 120 million years after sturgeon evolved.

“We’re trying to be real careful and real thoughtful about it. … It’s not like there’s going to be fish going in there tomorrow,” said Heath Rauschenberger , an ecologist at the U.S. Fish and Wildlife Service in Jacksonville . His office is part of a collection of federal and state agencies and nonprofit groups that have discussed restoring sturgeon for several years.

They may not even try to put the fish back, and would face difficult conditions in at least part of the St. Marys.

But researchers’ discovery this winter of one Atlantic sturgeon and one shortnose sturgeon — netted after nearly 1,500 hours of field work — has added to scientists’ curiosity about the blackwater channel that flows from the Okefenokee National Wildlife Refuge to the ocean.

The idea of bringing back the fish has sparked some local interest.

“I think it’s a great idea,” said Dean Woehrle , who lives near the river in Boulogne and co-chairs the St. Marys River Management Committee , a panel where local governments and residents from both states talk about river issues.

“They were there naturally. … It’s kind of like if God didn’t want them there, he wouldn’t have put them there.”

An avid boater for 30 years, Woehrle said some sturgeon and shad still spawned in the river until the early 1980s, when a drought lowered the river’s flow.

The fish get boaters’ attention as they leap through the air, sometimes landing in boats, said Altamaha Riverkeeper James Holland , whose river has an annual run of spawning sturgeon coming upstream in spring and summer from the waterway’s mouth near Brunswick.

“They all jump,” Holland said. “The sturgeon are extremely strong fish and they’ve got very strong tail maneuvers. If they slap you with that tail, you just might get hurt.”

Atlantic sturgeon, which have rows of bony plates and usually are full grown at 8 feet and a few hundred pounds, are valued more for caviar than for their meat.

Adults spend most of their lives in the ocean and travel inland to spawn at varying intervals.

The Florida border is near the southern end of their territory.

In the summer, temperatures in the St. Marys River can be much warmer than the 70- to 75-degree range they consider ideal, sometimes hitting the 90s, said Doug Peterson, a fisheries professor at the University of Georgia who studies sturgeon.

But the bigger problem for the fish, Peterson said, is that oxygen levels in the St. Marys are markedly too low.

Dissolved oxygen, as it’s called when it has mixed into a solution with water, should be at least three parts per million for sturgeon to be healthy. But in the St. Marys, the levels are often below two parts per million, Peterson said.

He said that often happens in other rivers because of fertilizer-like pollutants flowing into the water, but the reason in the St. Marys isn’t certain.

Peterson has spent two years studying whether the St. Marys and the nearby Satilla River have native sturgeon populations and whether they have the kinds of habitat that either Atlantic or shortnose sturgeon need. That research isn’t finished yet.

Using a field crew carefully setting up gill nets and trammel nets in prime spots for sturgeon, he has found a few dozen fish in the Satilla so far, which he said might reflect remnants of a local population.

But Peterson’s nets had come up empty in the St. Marys through hundreds of hours of work until this winter.

He said it’s very possible the two recent catches simply wandered in from the ocean and don’t represent a local population, but he plans a new round of netting in the same area to look for other fish.