How do you put a couple of pallid sturgeon into a romantic mood? Soft music? Candlelight? A comfy old sofa with a lot of fluffy pillows? If only it were that easy.
Biologists know that they've got to get some spawning out of the old pallids of the Missouri and Yellowstone river system. They haven't produced offspring that have survived to adulthood in at least the last 35 years.
Time is running out on this very endangered species. If they don't spark some romance and trigger some mating, the species will go extinct.
Biologists feel the key to producing young is something called the Spring Rise.
The Spring Rise came out of a 2000 Biological Opinion issued by the U.S. Fish and Wildlife Service on the effects of operations of the dams of the Missouri River on endangered species like the piping plover, least tern and pallid sturgeon.
The Biological Opinion said, in part, "Current operations, if continued without significant alterations, likely will cause further declines in other native species and likely will result in additional species listed as threatened or endangered. If more Missouri River species are listed in the future, operational conflicts and constraints will increase, while flexibility to manage the system will decrease."
According to Steve Krentz, a U.S. Fish and Wildlife Service supervisory biologist in Bismarck who leads the nation's Pallid Sturgeon Recovery Team, what is basically called for is a return to some semblance of what the Missouri was before the dams were put in place. Historically, the Missouri had higher flows sometime between late May and early July.
"Our recommendation first and foremost is you've got to get the Spring Rise and the lower summer flows to cue the spawning to see if we can get them to spawn in the wild," Krentz said. "That's the best hope from the sturgeon standpoint.
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"It's restoring some of those processes that went on before the dams and maintaining flows that provided those cues to spawn and the habitat formations that this species needs," he added. "It's the seasonal fluctuation of flows. Turbidity (muddy water) is important. The old Missouri River as it functioned is obviously the best habitat."
No one is suggesting that Fort Peck Dam, Garrison Dam or any of the other dams on the Missouri be removed. No one is suggesting the Spring Rise flood the countryside. There are many who fear the Spring Rise might do that.
Mike Ruggles, the Montana Fish, Wildlife and Parks fisheries biologist for Fort Peck Reservoir, was a pallid sturgeon biologist on the Missouri River below Fort Peck during the middle 1990s when the Biological Opinion was being put together. He recalled going to Culbertson once where all the fears of flooding boiled up at a public meeting.
"There were concerns about flooding, loss of irrigation sites, flooding in Culbertson, widespread erosion," Ruggles said. "I asked them, 'Is that what happened in 1997?' What they experienced in 1997 is about the peak of where the water would be under the Spring Rise out of Fort Peck Dam.
"They did have to move some pump sites. There was some bank erosion. But there wasn't flooding in Culbertson. The Spring Rise isn't going to flood people out," he said. "The Spring Rise would be once every three years and it's designed so we can cut back on flows if we need to in order to prevent flooding if conditions change."
The Spring Rise is necessary both to increase the flows in the river and to increase the water temperatures to the spawning range for pallid sturgeon. In short, the spring rise is necessary to put them in the mood for love.
"Water coming through the powerhouse at Fort Peck is clear and cold. That's good for species like trout, but it's not good for these river species like sturgeon, sauger and catfish," Ruggles said. "Having warmer, dirtier water is better for these river fish.
"The way the Spring Rise would work is to use stored water from Fort Peck that warms up before spawning time. Warmer, surface water from Fort Peck would be released over the spillway to mix with the water out of the powerhouse," he said. "We'd be looking to get the water in the river up to 68 to 70 degrees by the time it got down to Frazer and Wolf Point.
"The Milk River is putting out warm water that would mix with the warm water out of the spillway and the water out of the powerhouse as well," Ruggles continued. "The spillway could be backed off when the Milk is really pumping out a lot of water. Plus, the Milk would be putting out a lot of turbidity."
The result would be a strong pulse of high, muddy water that would lure pallid sturgeon far up the Missouri to spawn.
To do that, more water would have to be stored in Fort Peck than there is in the reservoir.
According to FWP's Ken McDonald, who chairs the Upper Basin Pallid Sturgeon Recovery Group, "The bottom of the spillway is 2,225 (feet of elevation). We figure you'd have to get the lake up to 2,230 — get 5 feet of head on it — to have the water to spill."
The current level is roughly 2,211 feet — far from the spillway level.
"We want the spring rise to get the pallid sturgeon to run as far up the Missouri as possible," Ruggles said. "It is believed that these fish are spawning too close to the headwaters of Lake Sakakawea. When the eggs hatch, the larval pallids drift downstream into the headwaters of the lake and when the water stops moving, the fish settle out in the mud and get buried there. They're suffocating in the mud and dying."
Krentz said no one knows exactly how far the larval sturgeon are being carried, except that it's believed it can be a long, long ways. No one knows how many are being lost to the headwaters of Sakakawea.
"The drift might be anywhere from 40 to 400 miles. It's not a single number," Krentz said. "A lot of it depends on their rate of development. As they fish hatch and go from egg to fry, they live on their yolk sac for the first few days as they drift. Then they need to switch over to a live diet. That's when we suspect their initial drifting is ceasing. They settle out on sandbars and other areas that have high invertebrate populations and zooplankton."
The Spring Rise is necessary to lure pallid sturgeon as far up the Missouri as possible to spawn so they have more miles of river to drift.
Right now, high flows, muddy water and a natural spring rise is cueing pallid sturgeon to run up the Yellowstone River. But when they do, they bump into Intake Diversion Dam, below Glendive. That means the short reach of the lower Yellowstone apparently isn't allowing the pallids to go far enough upstream for the young pallids to develop before dropping into the headwaters of Lake Sakakawea.
Sturgeon romance is needed at the right time and in the right place if pallids are ever to reproduce naturally in the wild. Think of the Spring Rise as the candlelight and soft music needed to persuade pallid sturgeon to cuddle up on their big watery sofas and make some much-needed love.
Mark Henckel is the outdoor editor of The Billings Gazette. Contact him at 657-1395 or at firstname.lastname@example.org.