Monitoring water quality and phytoplankton community composition and growth dynamics is needed in Bighorn Canyon National Recreation Area (BICA) because dense, persistent phytoplankton blooms are occurring annually between July and September throughout BICA as a result, in part, of land use and upstream activities that enhance eutrophication. These blooms might pose a direct threat to water quality, fisheries, and the health of people and animals in the park.

There is little data concerning the extent and severity of these blooms, and it is unknown whether they produce harmful cyanotoxins. Therefore, this project will perform a synoptic survey of water quality conditions, cyanotoxin occurrence, and phytoplankton bloom community composition across the park to determine how these blooms influence water quality, the potential environmental parameters that promote bloom development and toxicity, and the possible impacts of cyanotoxins and degraded water quality resulting from these blooms on humans and wildlife that inhabit or use water resources within BICA.