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DNA barcodes for assessment of the biological integrity of aquatic ecosystems
Citation:
BAGLEY, M. DNA barcodes for assessment of the biological integrity of aquatic ecosystems. Presented at Second International Barcode of Life Conference, Taipei, TAIWAN, September 17 - 21, 2007.
Impact/Purpose:
This research will be used to improve the precision and objectivity of taxonomic identifications of the benthic organisms used in stream bioassessments.
Description:
Water quality regulations and aquatic ecosystem monitoring increasingly rely on direct assessments of biological integrity. Because these aquatic “bioassessments” evaluate the incidence and abundance of sensitive aquatic species, they are able to measure cumulative ecosystem effects of chronic or intermittent pollutants in a way that water chemistry assays cannot. Reliance on morphological identifications has constrained greater adoption of bioassessment protocols due to limited availability of trained taxonomists, difficulty or inability to identify cryptic larval forms with high taxonomic resolution, and sample size limitations imposed by the time and cost of morphological analysis. Integration of DNA barcodes into aquatic monitoring and assessment programs provides a viable solution to each of these problems. We are comparing the accuracy, precision, and cost of taxonomic identifications based on DNA barcode and morphological approaches for an existing state (Maryland, USA) bioassessment program, focusing on aquatic insects in the families Ephemeroptera, Trichoptera, and Plecoptera. Importantly, morphologically cryptic aquatic larvae collected in streams are linked via DNA barcodes to taxonomically resolved adults vouchered at the Smithsonian Institution. Our results will be used to recommend strategies to integrate DNA and morphological approaches into bioassessment programs that optimally leverage available resources for specimen collection, taxonomic assessment, and data analysis.