How have states addressed algal taxonomic issues in their datasets?
Citation:
Lee, S. How have states addressed algal taxonomic issues in their datasets? Society for Freshwater Science, Philadelphia, PA, June 02 - 06, 2024.
Impact/Purpose:
This presentation will provide several examples and lessons learned from collaborations with state partners to work on water quality and biological condition assessments in freshwater bodies. The research involved efforts to resolve algal taxonomic issues to improve the application of algal data in assessments of biological condition in freshwaters. The long term importance of the findings is that management of consistent taxonomic data will make scientific evidence-based decisions possible. The presentation will be of interest to states, Tribes, and other organizations who desire to use algae to assess the biological condition of freshwater bodies.
Description:
Diatoms and soft algae have been collected by state monitoring programs across the United States to assess the biological condition of lotic and lentic water bodies. Some of the state programs have long-term records (i.e., decades) of algal taxonomic data. Over time, changes in laboratory contractors and algal systematics have contributed to challenges in maintaining consistent datasets that can be applied to biological assessment questions. The U.S. Environmental Protection Agency provided technical assistance towards examining taxonomic issues and resolving discrepancies within state algal datasets. Improvements in data quality and transparent documentation of how datasets are modified to "harmonize" taxonomy helped restore confidence in using algal data for state assessments. This kind of data modification has been called "post-hoc harmonization," which differs from harmonization embedded into a research plan from the beginning through upfront resources dedicated to ensuring consistent taxonomic data. Post-hoc harmonization is helpful but results in some loss of data resolution and usually cannot completely remove the variation in algal assemblage composition explained by laboratory or analyst. This presentation will focus on examples of post-hoc harmonization efforts and lessons learned that may help state programs make better use of their existing algal data and inform future collection and management of algal taxonomy, to improve monitoring and assessment of biological condition in freshwaters.