Pallid Sturgeon and the Role of the Proposed Program

Home Browse Search

were from the Missouri River, 9 percent from the Yellowstone River, 5 percent from the Mississippi, 14 percent from the Atchafalaya River and a combined 2 percent from the St Francis, Ohio, Kansas, Big Sunflower and the Platte (Steve Krentz, USFWS, 2000). It is interesting to note that American Rivers included the Missouri, Kansas, and Big Sunflower in their list of the top 10 most endangered rivers {I'M NOT SURE THIS LAST SENTENCE ADDS MUCH. THE PLATTE HAS ALSO BEEN LISTED BY AMERICAN RIVERS IN THE PAST}. Specifically, with regard to the Missouri River and Platte River confluence area a database for the pallid sturgeon is currently being refined for inclusion in the Program Baseline document. Care should be taken during this effort to ensure that "non - confirmed" reports of pallid sturgeon (i.e., angular accounts) do not result in an overemphasis on the Missouri River confluence area. The pallid sturgeon is very similar in appearance to the more common shovelnose sturgeon and there are some that believe they are members of the same species' CAN WE ADD A REFERENCE`? } . The species status of the pallid sturgeon has often been debated and geneticist and ichthyologists have \ r�� worked hard to develop methods to definitively differentiate the two species. Studies from the mid 1990's failed to differentiate significant genetic differences between the pallid and shovelnose sturgeon while more recent studies suggest genetic differences may exist. Although the species status has been questioned, the point raised here is that even experts have difficulty distinguishing the two species and to date there are only two occurrences of pallid sturgeon in the Platte which have been documented by experts. After considering the historic and current information regarding pallid sturgeon distribution and abundance it is clear that the Missouri and Mississippi Rivers have been their primary habitat. The Service has concluded based on the literature cited in their 1998? Missouri River Biological Opinion, "...that the pallid sturgeon was still fairly common in many parts of the Mississippi and Missouri Rivers systems until as late as 1967. The literature indicates that declines in populations have occurred coincident with the development of the Missouri and Mississippi systems for flood control and navigation." There is in excess of 73 million acre feet of storage on the Missouri River. The Service concludes that the Missouri River has been extensively modified with approximately 36 percent of the riverine habitat inundated by reservoirs, 40 percent channelized, and the remaining 24 percent altered due to dam operations. The above information suggests that the pallid may be being expatriated from its natural environment. If in fact this is true one would expect to see it moving into peripheral environments such as the Platte. The pallid sturgeon evolved in the diverse environments of the Missouri and Missippi Rivers (USFWS, 1993 Pallid Sturgeon Recovery Plan). Consequently, they appear capable of utilizing a broad range of habitats. The following data summary from pallid use sites is taken from the Missouri River Biological Opinions and illustrates this point. Water Temperature: 32- 86 degrees Fahrenheit Water Velocity: 0 -4.49 feet per second Rev. 1 Sept. 3, 2002 Draft R.B. 3 r\4 1% C* l5