Title

Effects of sand accumulation on invertebrate communities of the Salmon Trout River, Michigan

Document Type

Conference Proceeding

Publication Date

5-26-2011

Abstract

Increased fine sediments associated with watershed disturbances alter physical habitats in streams which may affect natural ecosystem processes and food webs. Reduced or altered food resources may negatively impact invertebrate consumers and propagate up to higher trophic levels in sediment-impaired streams such as the Salmon Trout River (STR) in Michigan. We compared monthly invertebrate abundance and biomass in replicate rock and sand-impacted habitats to quantify effects of sand accumulation on lower trophic levels in the STR. Total invertebrate abundance was 3x greater in the sand vs rock habitats, and collector-gatherers (Chironomidae, Oligochaeta) comprised the greatest proportion of invertebrate abundance in both habitats. Total invertebrate biomass was highly variable and slightly higher (1.2x) in rock vs. sand habitats. Proportionately, scrapers (Glossosoma sp.) and shredders (Pteronarcys sp.) dominated invertebrate biomass in rock habitats, while gatherers and predators (Hexatoma sp.) dominated biomass in sand habitats. Preliminary results suggest lower trophic levels in each habitat closely track dominant basal energy resources, which along with reduced physical habitat quality, serve to alter food webs in sand-impacted rivers.

Publication Title

North American Benthological Society 2011 Annual Meeting