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USEPA Regions Research Assessing Field Sampling and Analytical Procedures for Characterizing Risk Posed by Harmful Benthic Cyanobacteria in Streams and Rivers
Citation:
Nietch, C., Kristina Laidlaw, R. Labiosa, A. Tatters, H. Mash, J. Lu, J. Lazorchak, T. Sanan, E. Pilgrim, P. Weaver, AND L. Webb. USEPA Regions Research Assessing Field Sampling and Analytical Procedures for Characterizing Risk Posed by Harmful Benthic Cyanobacteria in Streams and Rivers. Benthic HAB Workgroup Meeting, Cincinnati (Virtual), OH, March 26, 2024.
Impact/Purpose:
Benthic harmful cyanobacteria blooms pose a significant threat to domestic animals, wildlife, and humans. U.S. states, tribes, and local agencies need consistent approaches to characterize relative risk and inform mitigation practices. USEPA is addressing this need with multi-year, multi-site field research and controlled experiments.
Description:
U.S. states, tribes, and local agencies need consistent approaches to characterize the relative risk posed by harmful benthic cyanobacteria proliferations and to inform mitigation practices. USEPA is addressing this need with multi-year, multi-site field research and controlled experiments. In 2023, research focused on evaluating in-stream sampling methods that quantify spatial extent at the reach scale and assess the toxin exposure risk from disturbing benthic mats. A stream mesocosm study designed to control the relative dominance of specific strains of benthic cyanobacteria was conducted in parallel with the field effort. Field measurements were scheduled among seven field crews, making multiple visits to seven pilot test sites across six states (CA/KS/OH/UT/VA/WA). Laboratory analyses are ongoing and include general water quality variables, pigments, microscope counts, DNA metabarcoding of periphyton samples, qPCR analyses for toxin biosynthesis genes, and cyanotoxin-specific analyses. All periphyton samples were collected such that measures are normalized to stream bed area and periphyton biomass. The same analyses were run on samples from the mesocosm study, but in addition, effects on macroinvertebrates and fish were tested. Preliminary results provide rationale for streamlining field sampling techniques so that more sites can be surveyed in 2024 and insight into the variation in benthic cyanobacteria growth forms, community structures, toxins, and their potential effects on stream biota to help guide recommendations for risk assessment in the future.
URLs/Downloads:
BENTHIC-HABS-SLIDES-3-26-2024.PDF (PDF, NA pp, 11041.211 KB, about PDF)https://www.epa.gov/habs/benthic-harmful-algal-blooms-hab-discussion-march-26-2024