NEOSHO, Mo. — A species that has existed since the time of the dinosaurs but that is having trouble hanging on in the 21st century will get a bit of a boost.
The Neosho National Fish Hatchery recently received new, circular water tanks for pallid sturgeon reproduction, and officials hope the tanks will help create a more successful breeding environment for the federally endangered species.
Bruce Hallman, environmental education specialist with the hatchery — the oldest operating federal hatchery in the country — said that the tanks previously used to house the sturgeon were large rectangles, but new recommendations from conservation officials and scientists indicate circular tanks might make a better breeding environment.
"Basically it's just going to create an endless path for them to be able to swim," Hallman said. "There will be a little current in there that will kind of mimic the river, and the thought is just that that's going to keep them a little happier."
The pallid sturgeon's natural home is the Missouri River and parts of the Mississippi River, and although they can grow large — up to 6 feet long and weigh more than 100 pounds — they are difficult to study because of murky water and the size of the rivers, Hallman said.
According to the U.S. Fish and Wildlife Service, which manages the federal hatchery and also is responsible for endangered species, the pallid sturgeon experienced a decline throughout its range because of river channelization, dams and other alterations that have destroyed or altered spawning areas, reduced its prey base and even altered water temperatures.
"They have been federally endangered for almost 30 years — 1990 was their entry onto the list that no one wants to be on," Hallman said.
Wildlife managers and fisheries biologists have worked to restore habitat, and also on captive breeding and restocking programs, but so far they have found almost no evidence of sturgeon reproduction in the wild.
"If they have found the rare cases where they've seen behavior that looks appropriate, later they haven't found the babies that would support that," Hallman said. "So there are just a lot of question marks with the whole program. It's a huge mystery in a lot of aspects."
When adult sturgeon are found and caught, they are brought to places such as the Neosho hatchery so that biologists can attempt to breed them, Hallman said. This can be difficult because the fish do not breed every year.
Young sturgeon raised at the hatchery are released into the lower Missouri river when they are at least 9 inches in length.
"They are also usually scrawny, so there is probably a food shortage for them in the wild," Hallman said. "So we are able to fatten them up and get them all healthy here."
Adult sturgeon brought to Neosho will now live in one of two larger tanks that will be 20 feet in diameter when assembled, Hallman said. They also received eight smaller tanks, about 3 feet deep and 6 feet in diameter, for the newly hatched fish.
"The newly hatched ones are maybe one-quarter of an inch long, very small, and they don't take up a lot of room," he said.
The number of pallid sturgeon the hatchery is able to raise in a year varies greatly, Hallman said.
"It's a very complex problem, and we're not here to solve the problem as far as the hatchery here," Hallman said. "Our main goal is to try to breed them and try to get some new families out there."
Hatchery employees have spent the fall removing the old tanks and preparing space for new tanks, he said.
"In the future I think we want to possibly double the number of small tanks to 16," Hallman said. "But right now, eight will be plenty to take care of them through the whole year."
Established in 1888, the Neosho National Fish Hatchery has raised more than 130 species, including many that are endangered, such as the Topeka shiner, the Ozark cavefish and mussels like the Neosho mucket. The hatchery also raises rainbow trout for Lake Taneycomo.