The effects of fish predation and algal biomass on insect community structure in an Idaho stream

To determine the affect of fish predation and food resource levels on lotic macroinvertebrates, a 2 × 2 factorial experiment was conducted. Treatments consisted of varied densities of fish and algal biomass levels placed in cage enclosures. Treatment interaction affected total taxa densities. Fish levels had an negative impact on some taxa densities and biomass, while algal levels had a positive effect. Although richness and evenness were not affected by the treatments, several functional feeding group parameters were altered.