Current ecological conditions Lubinski, K., R. Gaugush, S. Gutreuter, T. Owens, S. Rogers, P. Thiel, and J. Wlosinski. 1992. Current ecological conditions. Pages 50-63 in Proceedings of the Forty-Eighth Annual Meeting of the Upper Mississippi River Conservation Committee, Red Wing, Minnesota, March 10-12, 1992. Reprinted by U.S. Fish and Wildlife Service, Environmental Management Technical Center, Onalaska, Wisconsin, October 1993. EMTC 93-R021. 14 pp. (NTIS #PB94-123049) ABSTRACT Describing the status of the Upper Mississippi River is a continuing function of the Long Term Resource Monitoring Program. Some ecologically important characteristics that serve as indices of overall system status include depositional habitats, vegetation, invertebrates, fish biodiversity, and our capability to apply information to achieve ecological goals. Individual conditions, however, must be regarded as elements of a comprehensive ecological perspective. The filling of depositional aquatic habitats has been measured sufficiently to identify this as the major long term resource problem in navigation pools. However, extrapolating sedimentation rates from one location to another for the purpose of focusing rehabilitation efforts is problematic without additional hydrologic information. Many depositional habitats currently are at high risk of entering a successional phase that will be characterized by poor water quality and reduced aquatic vegetation. Changes in the abundance of submersed vegetation and invertebrates have been linked to droughts and floods, among other factors, recently, but the interpretation of long term trends is still limited by the short periods of time over which comparable observations have been made and a lack of experimental research. Zebra mussels pose a serious threat to native mussel populations, and their already widespread occurrence suggests that we need to shift our efforts from monitoring to identifying practical control measures. Biodiversity (species richness) of the fish community has declined less than that of the mussel community. Our capability to utilize ecological information in a proactive management strategy is improving. One of the first steps in the strategy will be the establishment of ecological objectives and action levels appropriate for a large floodplain river. KEYWORDS Upper Mississippi River, sedimentation, aquatic vegetation, zebra mussels, biodiversity, ecosystem management, monitoring