U.S. & Wildlife Service Pallid Status: Endangered

Pallid sturgeon evolved within the diverse environments of the Missouri and Mississippi Rivers at a time when flood plains, backwaters, chutes, sloughs, islands, sandbars, and main channel waters formed the large-river ecosystem. They were well adapted to living in large rivers where fluctuating environmental conditions, such as river flows, exist. Those same characteristics that enabled the

pallid to survive for thousands of Photo by Ken Bouc, Nebraska Game and Parks Commission years have also made them vulnerable to changes in the river that diminished spawning and nursery habitat. reproductive trigger for native nutrients. Under present fish - including the pallid conditions, the Missouri River is In the biological opinion on sturgeon. simply too fast and deep Missouri River operations, the throughout much of the lower U.S. Fish and Wildlife A modest increase of flows from basin to provide the shallow and recommends returning the river in the spring slack water habitat where young to more natural flows. Here is will also provide biological cues to fish can rest, feed, and grow until how the Service’s encourage pallid sturgeon to they are capable of negotiating recommendations will benefit . main channel currents. pallid sturgeon: Lower summer flows are Flow modifications in conjunction The Service has recommended an expected to benefit pallid with habitat restoration are increase of warm spring flows sturgeon in the lower 800 miles of critical to ensure the continued from spillway to the river by providing additional existence of this Missouri River maximize the amount of warm slow, shallow water to allow resident. water habitat available below the young-of-the-year fish to grow dam. Reproduction by warm large enough to survive through water species such as the pallid the first winter. sturgeon has been limited due to Larval and fingerling pallids need U.S. Fish & Wildlife Service cold water coming from the dam. P.O. Box 25486, DFC Warm water intentionally spilled to remain in shallow water areas Denver, Colorado 80225-0486 over the spillway will act as a containing high concentrations of http://www.r6.fws.gov November 2000