2011 National Wetland Condition Assessment Diatom Dataset

Diatom assemblages are excellent indicators of wetland condition and have been widely used to assess wetlands around the world. Difficulty in diatom species identification and nomenclature has led to major inconsistencies in taxonomic datasets among different analysts and labs. These inconsistencies have prevented the use of diatoms in long-term and/or large-extent assessment programs, such as the United States Environmental Protection Agency’s (U.S. EPA) National Wetland Condition Assessment (NWCA) that require multiple analysts/labs. A solution using trait-based indices that do not rely on species level identification is promising. Trait-based indices based on genus-level data have the advantage over classic species-based indices as they require less work-effort and expertise, and therefore are less costly to analyze. Using genus-level data is also more reliable for bioassessment because it is less prone to taxonomic inconsistencies from using multiple analysts. We plan to use the genus-level diatom data from the 2011 NWCA to develop efficient and cost-effective diatom indicators for use in future NWCA surveys.  

Impact/Purpose

For large-scale and long-term assessment programs that require multiple taxonomic laboratories to process samples, such as the United States Environmental Protection Agency’s (U.S. EPA’s) National Wetland Condition Assessment (NWCA), discrepancies in species-level identification or nomenclature has prevented the use of diatom data in national assessments. To address this problem Luisa Riato and Amanda Nahlik of EPA-ORD-PESD, and Alan Herlihy of Oregon State University, plan to investigate developing diatom multimetric indices (MMIs) for use in the NWCA, using genus-level diatom taxonomy and trait-based autecological information, that will circumvent the problem of taxonomic inconsistencies in national diatom datasets.

Citation

Riato, L., A. Herlihy, AND A. Nahlik. 2011 National Wetland Condition Assessment Diatom Dataset. U.S. Environmental Protection Agency, Washington, DC, 2025. [DOI: 10.23719/1532177]

DOI: 2011 National Wetland Condition Assessment Diatom Dataset