Caddo Lake: The open-mouthed dinosaur-era paddlefish is welcome back!

Deep beneath the surface of Texas' only naturally formed lake there used to swim a massive, open-mouthed dinosaur-era fish with a long snout and prized caviar. Now, decades after the paddlefish was almost completely wiped out, it's coming back to Caddo Lake.

This time, the fish will be closely tracked by scientists, researchers and students in 20 schools as part of a broad collaboration between private, state and federal agencies attempting to revitalize a long-damaged ecosystem by changing the water releases from a nearby dam. Scientists believe if the paddlefish survive it will be a sign the ecosystem is recovering.

Rick Lowerre, president of the Caddo Lake Institute, a private nonprofit established in 1992 by The Eagles' frontman Don Henley to help preserve and revitalize the wetland area where he grew up, said the paddlefish will not "reverse what humans have done."

"It'll be very important if we can show ... that we can reintroduce and recover this fish, more as a symbol of returning the system to a healthy condition," Lowerre said.

The paddlefish experiment is part of a larger five-year project with the U.S. Army Corps of Engineers to change how water is released from the Lake O' the Pines Dam. Traditionally, the Corps released water largely to prevent flooding, especially in nearby Jefferson, a town of old time general stores, antique shops and bed and breakfasts.

As a result, the Corps failed to account for the river's natural flows, explained Laura Huffman, director of the Nature Conservancy in Texas, another group involved in the project. The stronger flows, or "spring pulses," signaled to the paddlefish it was time to migrate to their spawning grounds. When the flows disappeared, so did the paddlefish.

A new agreement with the Corps of Engineers and a local water provider will allow the releases to more closely mimic the watershed's natural flows while also providing flood control. The belief is this will allow the paddlefish, long on the state's list of threatened marine life, to once again flourish, Huffman said.

"It's the balance that's so important," she said. "When an ecosystem gets out of balance certain species will dominate that shouldn't dominate."

The Army Corps of Engineers is reaching similar agreements elsewhere in the country to redirect water releases as the ecological damage from dams becomes more apparent. By reintroducing up to 50 paddlefish into Caddo Lake, scientists and researchers will be able to test the theory that by more closely mimicking nature, some of the native habitats, ecosystems and wildlife that disappeared will start to recover.

The U.S. Fish and Wildlife Service inserted transmitters into the paddlefish, which can grow to be 7-feet long and 200 pounds. Three antenna-like receiving towers along different parts of the watershed will help scientists monitor the fish.

Students, meanwhile, will track them on the Caddo Institute's website. Some have already "named" their fish, and walk around with "Save the Paddlefish" signs. Local stores have collection boxes on their counters to raise money for the $100,000 project.

The Texas Parks and Wildlife Department will track the fish from small boats in areas of the 26,000-acre lakewhere there are no receivers. In the late 1980s and early 1990s, the state agency released about 300,000 baby paddlefish into Texas waters, including Caddo Lake. It's unclear that any remain in the lake today, said Timothy Bister, a district fisheries biologist with the agency.

"About half of the fish that were tagged with transmitters were lost downstream within eight months of stocking," he said.

But the paddlefish thrived in the lake in the 1800s when little Jefferson boasted Texas' largest lake port and cotton flowed on steamboats and rafts down to New Orleans. The fish survived various changes that people made to the lake over the years. In the 1950s, though, when Lake O' the Pines was built and the flows were regulated, the paddlefish finally disappeared.

"There's no point in even doing this experiment unless we have those increased flows," said Jim Neal, program director for the Caddo Lake Institute. "It's going to have a really positive impact on a lot of things."