HERMANN — It’s a cool and exceptionally foggy November morning as Andy Plauck and two fellow employees of the U.S. Fish and Wildlife Service slip their net boat, “Big John,” into the chilled Missouri River at the Hermann ramp. They begin working their way through the fog to count pallid sturgeon by checking gill nets set strategically below the surface of the Big Muddy.
The pallid sturgeon is in trouble. That much is certain. In fact, sturgeon species worldwide are in decline, largely because of the same set of man-made challenges. Only one species, the shovelnose sturgeon, has survived relatively unscathed.
To trace the history of large rivers around the world is to chart the decline of these bottom dwellers. The pallid sturgeon’s fate is tied to the management of the Missouri River. Once a wide and shallow river consisting of twisting and braided channels, the Missouri would swell across its flood plain each spring, fed by the melting of the previous winter’s snow.
Spurred by the spring surges, female sturgeon ready to spawn make their way upriver through murky water to seek safe havens where their eggs can develop and hatch. Each spawning season is critical; females can take up to 12 years to reach spawning maturity, and they spawn only every three years thereafter.
These days, biologists worry whether the pallid sturgeon can sustain itself as a species in an environment radically different from what it was before the Missouri River was channelized and its banks fortified by levees that protect river towns and farm fields. The river has been stocked with pallids born in hatcheries, but it remains to be seen whether that effort will be enough, given the lack of suitable shallow-water habitat upon which the sturgeon rely. The few remaining pallid sturgeon also face the threat of being snared by anglers looking for highly coveted sturgeon caviar, which can fetch a hefty price.
The pallid sturgeon isn’t alone. Two other endangered species — the piping plover and the least tern — also depend on favorable releases from upstream reservoirs to ensure their reproduction.
The U.S. Geological Survey, the Fish and Wildlife Service and the Missouri Department of Conservation all are involved in monitoring Missouri’s pallid sturgeon population. The U.S. Army Corps of Engineers maintains the river and pays for much of the sturgeon research.
Under the Endangered Species Act, the federal government is compelled to fight the endangered species’ decline, said Aaron DeLonay, an ecologist with the U.S. Geological Survey. But many of the scientists fighting for the fish do it because they want to.
“It is a unique species that has taken thousands, maybe millions, of years to evolve,” DeLonay said. “And once it is gone, it is gone forever.”