The objectives of the benthic macroinvertebrate (BMI) research are:

1. 1) To develop a long-term data set on BMI populations and community assemblage structure along the study reach of the Bighorn River (Map 1) by collecting repeatable, quantitative, baseline data using standardized methods (Photo 1).

• What historical BMI data has been collected and how can this be used in comparison to current communities? How can we relate these biological indicators to spatial and temporal trends in aquatic habitat health as influenced by macrophyte beds, algae,aquatic invasive species, sedimentation, water quality, dissolved gases and regulated flows?

1. 2) To evaluate both temporal and spatial BMI patterns to help BHRA understand how they have been affected by water quality, hydrology, flow management and temperature regimes. The result will be a better understanding of the overall biological health of the Bighorn River and its determinants.