River change could help endangered fishby Cara Hetland, Minnesota Public Radio
For the first time, the U.S. Army Corps of Engineers is trying to mimic the natural flow of the Missouri River. The corps has been holding back water for several days at Gavins Point Dam in South Dakota. It's one of six dams in the upper basin. For the next several days the corps will release large amounts of water creating a higher flow just like a spring rain. Researchers call that a pulse and say that's what tells fish it's time to spawn.
Gavins Point Dam, S.D. — Herb Bollig is passionate about saving fish. He runs a fish hatchery near Yankton, South Dakota. His job is to save the endangered pallid sturgeon.
"To me it's somewhat unethical to let a species die out. Where do you draw a line in the sand and say, 'Ok, we're not going to accept this any longer. We can save a lot of these species,'" says Bollig. "The pallid sturgeon is basically an indicator species of what's happening in the Missouri River. These aren't the only fish that are on the decline," he says.
The pallid sturgeon is a giant pre-historic looking fish that can weigh up to a hundred pounds. They can live for 70 years and grow about six feet long. They have a shark-like tale and wide fins. Their mouth is on the underside of their long flat nose. A female doesn't produce eggs until it's 14 or 15 years old.
It's been 30 years since the pallid sturgeon spawned on its own in the Missouri River. For the last 14 years Herb Bollig has artificially spawned the pallid sturgeon. Last year 250,000 baby sturgeon or fry hatched here. Most were sent to other hatcheries along the Missouri River. For the first year they are raised in tanks and then transferred to the river.
Bollig says the pallid sturgeon need help reproducing because their native Missouri River has changed.
"They're wanting to go up to an area that's called natal spawning areas where they used to spawn historically but they can't get there because the dams are in the way. You could probably move them or maybe put fish ladders in the dam but when they got to those natal spawning areas they're different too," says Bollig. "There's mud or silt in these gravely rocky areas. A lot of them are completely changed to the point the fish wouldn't recognize where it was supposed to spawn in the first place," he says.
There are six earthen dams on the Missouri River in the Dakotas and Montana. The dams created a fishing haven in the upper basin states and is considered an unexpected multi-million dollar industry that came as a result of the dams. The dams were built for flood control and barge traffic down stream.
How to save the pallid sturgeon has been a sometimes heated debate. Paul Johnston, U.S. Army Corps of Engineers spokesman, says landowners down stream don't have to worry about flooding as water levels rise over the next two weeks.
"We're looking at an increase in the reach from Gavins Point to just past Omaha of two-and-a-half feet and an increase in stages in mid-Missouri in the range of a foot. But with the tributaries falling off the river it's going to be lower in ten days from now than it is today so folks will see no impact at all down stream," says Johnston.
Missouri's Attorney General filed a lawsuit to stop the increased water flow. He worries higher river levels will flood fields. But a judge didn't issue an injunction before the change began. Some biologists say it'll take 15 years before they know if the pulse does trigger the sturgeon to spawn. But Paul Johnston can't guarantee it'll happen every spring.
"It's going to continue for a while and we have a number of monitoring teams checking the physical response of the river as well as the biological response. It's going to take a little bit of time to figure out the biological response," says Johnston.
Some pallid sturgeon in the Missouri river are tagged so researchers can track their movements. Biologists will be watching the sturgeon to see if the higher water this spring is the trigger the fish need to spawn on their own.
- Morning Edition, 05/17/2006, 7:50 a.m.