The Pallid sturgeon (Scaphirhynchus albus) is a ray-finned fish and is one of our many endangered species. It is found in the waters of the Missouri and lower Mississippi River basins of the United States. Its pale coloration gives rise to its name and it is closely related to the more common shovelnose sturgeon (Scaphirhyncus platorhynchus).
The Acipenseridae (sturgeon) family of fish originated during the Cretaceous period 70 million years ago. Pallid Sturgeons have remained basically unchanged and considered a relic of the dinosaur era. It even looks like a dinosaur with its flattened, shovel-shaped snout, bony plates and long tail that looks like it belongs on a reptile. The pallid has been called “one of the ugliest fish in North America”.
The fish is similar in appearance to the shovelnose sturgeon. The Pallid’s mouth is toothless and positioned under the snout like other sturgeons so they can suck up small fish and other food items from the bottom of the river. Its known habitat extends starting from the Missouri River in central Montana to St. Louis, the Yellowstone River of eastern Montana, and the Mississippi River around St. Louis all the way to the Gulf of Mexico. The pallid sturgeon boasts to be one of the largest fish found in these river systems.
This member of the Sturgeon family is much larger averaging between 30 and 60 inches (76 and 150 cm) in length and can weigh up to 85 pounds (39 kg) when matured which takes 15 years to reach maturity. They don’t spawn frequently or on a set time schedule so this may affect their population numbers. Once they are born, barring an untimely demise, they can live up to a hundred years.
The pallid has managed to survive over millions of years withstanding events that caused many other species of fish to go extinct. Even still, their future is still uncertain. Populations of the pallid sturgeon are so small now that one of these big fish are rarely seen or caught by fishermen today. Habitat loss caused by man’s intrusion is blamed as the primary cause in the decline of populations.
Pallid sturgeons evolved for millions of years in a natural river system that had waters with meandering, braided channels and backwaters which provided different depths and flow velocities. Their habitat has been altered by dams that modify flows, reduce turbidity and lower water temperatures in vital habitats. The river habitats of the Missouri and Mississippi also have been altered by various channels and construction of dikes that narrow the rivers and cut-off backwater areas.
The impounded waters created by the addition of man-made structures, apparently do not meet the requirements of the species and successful reproduction has never been documented. It is also likely the forage base once used by pallid sturgeon has been altered affecting growth and reproduction. The largest remaining populations of pallid sturgeon appear to be in the upper Missouri River above Ft. Peck Reservoir in Montana, in the Missouri and Yellowstone rivers above Garrison Reservoir in North Dakota and Montana, in the Mississippi River below St. Louis, Missouri and near the Old River Control Structure in Louisiana.
The Pallid was listed as an endangered species on September 6, 1990 in accordance with provisions of the Endangered Species Act of 1973 (National Paddlefish and Sturgeon Steering Committee 1992). River sturgeons that were captured in the Mississippi River at Grafton, Illinois about the early 1900’s report only 1 in 500 were pallid sturgeons. The species continued to decline even further with development of dams and reservoirs on the Missouri River. There are only remnant populations of pallid sturgeon remaining in each of the remaining river habitats.
It is doubtful that any natural reproduction has occurred during the last decade (National Paddlefish and Sturgeon Steering Committee 1992). The first Pallid sturgeons to be successfully artificially spawned were in Missouri in 1992. A number of Federal and State hatcheries are conducting studies they hope will benefit management of the pallid. The studies include methods to improve spawning techniques in order to insure survival of brood stock and to increase production of viable eggs and fry.
Finding wild spawned pallid sturgeon gives biologists hope that efforts to restore the side channels and floodplain habitats along the lower Missouri River are being successful. In the summer of 1999, Jim Milligan and his staff of the U.S. Fish & Wildlife Service, Fisheries Resources Office in Columbia, MO were able to collect the first known wild larval pallid sturgeon from the lower Missouri River. While performing a study, a search at the Lisbon Bottoms Unit of the Big Muddy National Fish and Wildlife Refuge reaped a special reward. A young sturgeon was collected in a restored side channel (aka as a habitat bead) where biologists and environmentalist are trying to recreate habitats.
They are creating habitats essential to the continued existence of this ancient species but these habitats will be beneficial to many different species. The location where the young sturgeon was spawned may not be known but what it is known the shallow off-channel habitats provided by the Lisbon Bottoms chute were being used by the young sturgeon as a refuge from the swift main channel currents.
Federal and state agencies are also working on identification of foods and feeding techniques to hopefully improve growth and survival of both fingerling and adult Pallid Sturgeon fish (National Paddlefish and Sturgeon Steering Committee 1992). It is due to the dedication of so many, that we are slowing but surely reversing destruction we have caused on this planet. Much needs to be learned and so much more work needs to be done.
Due to the efforts of those concerned along with dedicated volunteer groups such as Friends of the Big Muddy, wildlife refuges, habitats, and sanctuaries are being recreated to help many species find a home among us to survive and replenish their numbers instead of fading into history. I have worked with Friends of the Big Muddy in the past and hope to do more in the future.
I encourage everyone to look inside yourself and find a way that you, too, can help. There are many organizations that work on habitats; others dedicated to recycling; still others promoting a green way of life. Everyone can do something. Even if only a single drop of water is placed in a bucket at a time, eventually the bucket will become full.
The information used to bring you this article is provided by the men and women working hard to preserve this species as well as many others. To them we all owe our gratitude. Reference: National Paddlefish and Sturgeon Steering Committee. 1992. Framework for the Management of Conservation of Paddlefish and Sturgeon Species in the United States. U.S. Fish and Wildlife Service, Washington, D.C.