Diatoms of North AmericaApplication of diatom multi-metric indices to state monitoring data
Description: Diatoms are sensitive to changes in
environmental conditions and can be used to evaluate the biotic
integrity of streams and rivers. Carlisle et al. (2022) recently
developed multi-metric indices (MMIs) for three aggregated level II
ecoregions in the conterminous United States. These MMIs improved upon
previous efforts to develop diatom-based bioassessment tools by modeling
natural variation, removing metrics sensitive to taxonomic
inconsistency, and being made publicly available via a web-based
application through which independent data can be entered and used to
assess biotic integrity. In this webinar, we describe the application of
Colorado state diatom counts since 2004 to these MMIs. We walk through
each step of using the web-based application with independent state
data, including navigating the interface, assigning site identifiers
that are consistent with the National Hydrography Dataset, updating
diatom taxonomy, and computing MMI scores. Using the national MMIs, we
found that 62% of samples across the state of Colorado reflect possible
disturbance of diatom biotic integrity. Phosphorus and conductivity were
the most dominant stressors related to diatom disturbance in Colorado
streams. The present work represents the first application of
independent state monitoring data to the national MMIs and provides
guidance for how other states and regions can use these bioassessment
tools.
Target audience: Water managers,
policymakers, researchers, and others interested in applying regional
diatom data to publicly available tools for assessing biotic integrity.
