| This study examines the effects of fine sediment deposition on benthic invertebrates. Despite numerous studies identifying deposited sediment as a factor altering benthic invertebrate communities, it is not fully understood why some taxa are more tolerant or better adapted to increases in sediment deposition. As a result, there is no universal metric that can be applied to stream ecosystems to determine severity of sediment impacts. Therefore determinations of metrics that can be specifically used to identify sediment as the factor affecting the benthic invertebrate community is warranted. Benthic invertebrate biomonitoring metrics and species traits composition along a sediment deposition gradient were examined. Additionally the sensitivity of select benthic invertebrate taxa to sediment deposition was examined. Several metrics were determined to be useful in identifying the effects of sediment deposition as they were significantly correlated and responded consistently to increasing fine sediment deposition across seasons. The metrics % burrower and % Chironominae of chironomidae were positively associated with increasing fine sediment deposition. While the metrics: % EPT, EPT abundance and % Orthocladiinae of Chironomidae were negatively associated. Additionally several species traits were associated with increased sediment deposition. The species traits: plastron respiration, elongate body form, depositional rheophily and predation were positively associated. While the traits: univoltine, abdominal gill placement, flattened body form, gills present, gill respiration, slow- seasonal development, mulitvoltine, plate- like gills, strong swimmer, streamlined body and erosional rheophily were negatively associated. Therefore, species traits patterns and certain biomonitoring metrics may lead to diagnostic bioassessments of deposited sediment impacts in lotic environments. |
