The pallid sturgeon (Scaphirhynchus albus) is a large riverine fish that has survived for millions of years in large river systems. When one first sees a pallid sturgeon, its prehistoric roots are evident. The back and sides of pallid sturgeons are grayish-white, they have a compressed rostral area, a long slender tail and are armored with five lengthwise rows of scutes (bony plates instead of scales). Their mouth is located in a ventral position just forward of the eyes, is toothless and adapted for sucking small fishes and invertebrates from river bottoms. Pallid sturgeon can reach weights up to 80 pounds and reach lengths of 6 feet. Pallid sturgeon resemble the closely-related shovelnose sturgeon (Scaphirhynchus platorynchus) in body shape, yet shovelnose sturgeon rarely exceed 8 pounds, and are predominantly brownish in color.
Pallid sturgeon appear to prefer large free flowing turbid rivers that still have a relatively natural flow regime, that is an increase in flow during the spring months following the runoff from snow melt. Some feel this spring rise is a trigger for this species to begin moving upstream to spawn. Spawning seems to be limiting this species ability to maintain it’s population size. These fish are slow to sexually mature; males reach sexual maturity at around 7-9 years, with up to 3 years between spawns. Females are not expected to reach sexual maturity until they are 7-15 years old, with up to 10-year intervals between spawning.
Historically, pallid sturgeon were found in the Missouri River from Montana to St. Louis, Missouri; in the Mississippi River from above St. Louis to the Gulf of Mexico; and in the lower reaches of other large tributaries, such as the Yellowstone, Platte, Kansas, Ohio, Arkansas, Red, and Sunflower; and in the first 60 miles of the Atchafalaya River. As lands along these rivers were developed and the need for flood control, irrigation and hydro-power increased, multiple dams were constructed. In many areas, these dams effectively blocked upstream movements and altered the river below them. The construction of Intake Dam in 1905 on the lower Yellowstone is attributed with blocking pallid sturgeon movements upstream and thus reducing their current range in the Yellowstone River basin.
Currently pallid sturgeon populations are fragmented by dams on the Missouri River. Pallid sturgeon are scarce in the upper Missouri River above Ft. Peck Reservoir; in the Missouri and lower Yellowstone Rivers between Ft. Peck Dam and Lake Sakakawea; in the Missouri River downstream of Gavins Point Dam; and in the Mississippi and Atchafalaya Rivers.
The substantial habitat alterations resulting from dams and channelization of large rivers are believed to be the major causes of this species decline. In fact, the decline in pallid sturgeon abundance was notable enough to warrant their listing as a Federally endangered species in 1990 (55 Federal Register 36641; September 6, 1990). Following this listing, the U.S. Fish and Wildlife Service (USFWS) along with many State Game and Fish Departments have coordinated efforts to help recover pallid sturgeon. Following is a brief overview of those efforts.
1993 - Pallid Sturgeon Recovery Plan (10 megabyte PDF file) developed. This plan outlines the steps needed for recovery of this species.
1994 - Approximately 7,000 pallid sturgeon fingerlings, reared at Blind Pony Hatchery in 1992 and stocked into the Missouri and Mississippi Rivers. For more information contact: Kim Graham, Missouri Department of Conservation, Fisheries Research Section, 1110 S. College Ave., Columbia, MO 65201, (573)882-9880, Ext. 3227, email@example.com
1995 - Efforts to collect adult pallid sturgeon are undertaken in the upper reaches of the Missouri and Yellowstone Rivers. These fish are to be used as broodstock for future stocking efforts.
1997 - Four hundred and twelve 10 inch pallid sturgeon were stocked in the lower Platte River near Highway 50. These fish came from the Missouri Department of Conservation Blind Pony Hatchery.
USFWS first attempts to spawn the pallids occurred in 1997. A single female was induced and eggs were recovered. A power failure occurred the night following spawning and all eggs were lost at Garrison Dam National Fish Hatchery (NFH).
1998 - 17,500 larval pallid sturgeon were hatched at Garrison Dam NFH. The fry were flown to Gavins Point NFH for further rearing.
Eighty-four 6 year old pallid sturgeon raised at the Gavins Point NFH were stocked in the lower Platte River.
A total of 1514 one-year old pallid sturgeon were stocked in seven locations in the upper basin; three above Fort Peck reservoir and four sites on the lower Yellowstone River and the Missouri River between Lake Sakakawea and Fort Peck Dam.
1999 - During early April, crews from Montana Fish, Wildlife and Parks and Fish and Wildlife Service were at the Yellowstone River Confluence and captured 13 pallid sturgeon. Eight of the fish were delivered to Garrison Dam NFH for spawning this spring.
2000 - Approximately 400 juvenile and six adult pallid sturgeon from Gavins Point NFH were stocked into the Missouri River below Fort Randall Dam, South Dakota. These fish will be utilized in a study to better determine their habitat requirements and improve our understanding of some of their life history.
USFWS biologists found pallid sturgeon larvae confirming the first known reproduction of the pallid sturgeon in the Lower Missouri River in at least the last 50 years.