TA1 Developing Suspended and Bedded Sediments Criteria
256 Portland Ballroom
8:00 AM - 12:00 PM, Tuesday
() Developing biological criteria for sediment management in midwestern USA streams.
Rabeni, C1, 1 University of Missouri, Columbia, MO, USA
ABSTRACT- The development of biological criteria for managing effects of excess sediment on aquatic biota in midwestern USA streams will require a dual effort where effects of suspended materials are differentiated from those of bedded sediments. This talk reviews our efforts to begin criteria development for Missouri streams. For suspended sediments, we performed a literature-based modelling effort where concentration-duration graphs of responses of native fishes were superimposed on known sediment conditions from various ecoregions and under different land use scenarios to give a "first cut" estimate of potential problems. For bedded sediments we conducted several field tests to evaluate community response of invertebrates and fishes to a continuum of sediment amounts. A sediment biotic index was developed for invertebrates. Fishes were more variable in their responses to excess sediment and our efforts now focus on developing indices based on functional responses of trophic and reproductive guilds. Progress in this area requires a much greater effort in understanding reference sediment conditions within watersheds and between ecoregions, the relative influence of various land use activities, and the ability to separate biological effects of sediment from the myriad of other potential stressors that often accompany excess sediment.
Key words: fishes, sediment, invertebrates