Missouri River IA 06-WEM-1715

Assessment Comments

Assessment is based on (1) surveys of Nebraska fisheries biologists, (2) consultation with DNR staff and (3) results of fish tissue (RAFT) monitoring near Little Sioux in 1997.

Basis for Assessment

Continued to assess support of the Class  B(WW) aquatic life uses as PS due to habitat alterations and  flow modifications that resulted from development of the river  for navigation uses in the mid-Twentieth Century.   This assessment was presented to the Nebraska fisheries biologist for the Missouri River and to DNR/EPD staff with historical involvement with Missouri River issues.   These professionals agreed with the assessment that aquatic life uses are "partially supported."  The habitat alterations are due to channelization of the river, while the flow modifications are primarily due to control of river flows through the system of mainstem dams upriver from Sioux City.   Also, continue to assess support of fish consumption uses as FS based of 1997 RAFT sampling near Little Sioux which showed  that levels of all contaminants in the composite samples of carp fillets and flathead catfish fillets were less than 1/2 of the respective FDA action levels.