Missouri River IA 06-WEM-1708

Assessment Comments

Assessment is based on (1) surveys of Nebraska fisheries biologists, (2) consultation with IDNR staff and (3) results of fish tissue monitoring.

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 channelization of the river, while the flow modifications are due primarily to control of river flows  through the system of mainstem dams upriver from Sioux City.   Assessed support of the fish consumption uses as FS based on  results of RAFT sampling in 1993 at Long's Landing near Council Bluffs that showed levels of all contaminants less than 1/2 the respective FDA action levels in the composite sample of carp fillets.