In a surprising setback to farmers and barge shippers along the lower Missouri River, government biologists on Thursday affirmed the need for more shallow waters to ensure survival of the endangered pallid sturgeon.
The Interior Department’s Fish and Wildlife Service said that beginning next July, flows should be no greater than 25,000 cubic feet per from the Gavins Point Dam on the South Dakota-Nebraska border.
That level would be too shallow for grain-laden barges carrying multimillion-dollar cargo toward the Mississippi River at St. Louis. Because barges need flows of about 28,500 cubic feet per second to maintain a consistent depth for operating, the industry says low flows would halt traffic along the river in Nebraska, Iowa, Kansas and Missouri.
The biological opinion represents the agency’s final word on what must be done to trigger spawning and maintain a survivable habitat for young sturgeon.
The full impact of the findings was not immediately clear. But the Army Corps of Engineers has said it will use them to update river operations that have been virtually unchanged for more than four decades.
“The corps’ actions continue to appreciably reduce the likelihood of both survival and recovery of the species, thus jeopardizing the continued existence of the pallid sturgeon in the wild,” the Fish and Wildlife Service said.
In 2000, the agency said the sturgeon as well as two bird species, the endangered interior least tern and the threatened piping plover, could survive only if waterflow changed to mimic conditions before the Missouri was dammed and channeled.
Those conditions included a spring rise in the river from the snow melt to trigger spawning and a lower level in the summer establishing a suitable habitat for young sturgeon.
