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Poster: Regional Efforts to Use Sediment Diatoms as Biological Indicators of Lake Condition in the Northeastern US
Citation:
Lee, S., N. Schulte, M. Potapova, S. Spaulding, B. Block, B. Jessup, K. Salk, B. Pickard, H. Snook, E. Nering, K. Merrell, M. Enache, AND D. Charles. Poster: Regional Efforts to Use Sediment Diatoms as Biological Indicators of Lake Condition in the Northeastern US. North American Lake Management Society, Erie, PA, October 23 - 26, 2023.
Impact/Purpose:
This is a poster presentation for the 2023 North American Lake Management Society (NALMS) meeting in Erie, Pennsylvania.
Description:
Diatoms are excellent indicators of water quality and can be used as a tool for biological assessment. Aquatic ecosystems span across state boundaries and the northeast states have a long-standing interest in taking a regional approach to developing water quality criteria for lakes using sediment diatoms as biological indicators and to understand historical changes in lake condition. Diatom datasets from multiple sources require harmonization of taxonomy, the names used to identify taxa observed in lake samples, to ensure that the datasets are scientifically credible. In Phase 1 of this project, we merged datasets from multiple states and developed a data clean-up process to reconcile diatom taxonomy used by different laboratories, which will minimize errors that obscure diatom responses to water quality. In Phase 2, we worked on applying the harmonized lake sediment diatom data from Phase 1 to support development of biological indicators for nutrients and aquatic life use support. During Phase 2, the project team found some promising results with threshold responses of sediment diatoms to phosphorus enrichment. It was more difficult to discern the historical changes in regional lake condition by comparison of diatoms from the tops (modern condition) and bottoms (past condition) of sediment cores. This led to additional investigation about the depths of sediment cores needed to obtain bottom core intervals corresponding to time periods prior to major human disturbances and what factors most influence sediment accumulation rates of northeast lakes. Additional research into settlement and colonial land management history of the northeast also improved target date estimation to around the 1790s when commercial agriculture and small industry were more common in the region. This effort resulted in a harmonized diatom dataset, as well as analytical and conceptual foundations to support next steps for northeast state partners to work on developing assessment tools and biocriteria using sediment diatoms that are ecologically relevant and not limited to state boundaries.