HR: 11:30h
AN: NB22C-05    [Abstracts]
TI: Do the Choices for Field, Lab, and Data Analysis Methods Affect the Site Assessments in Biomonitoring Programs?
AU: * Silldorff, E l
EM: esilldorff@princetonhydro.com
AF: Princeton Hydro, 1108 Old York Rd, Suite 1 PO Box 720, Ringoes, NJ 08551 United States
AU: Herbst, D B
EM: herbst@lifesci.ucsb.edu
AF: Sierra Nevada Aquatic Research Laboratory, University of California Route 1, Box 198, Mammoth Lakes, CA 93546 United States
AB: Broad differences remain in the field, lab, and data analysis methods used for bioassessment programs across local, state, national, and international boundaries. Recent calls for direct comparisons among these methods have begun to be fulfilled, including performance-based evaluations, but such comparisons remain limited to a handful of studies. Here, we present the results from our research on 3 intensive methods currently used by California bioassessment groups. These 3 methods were simultaneously used to collect and process samples from the same 40 streams in the eastern Sierra Nevada. The resulting data from each method were then analyzed using both multi-metric IBI and RIVPACS-type multivariate predictive models. Although the field and lab methods differed with respect to replication (1, 3, or 5 composite samples per stream), level of identification (family vs. genus for Chironomidae), and number of individuals processed per site (500 vs. 900 vs. 1500), all field/lab protocols clearly discriminated between independently identified reference and impaired streams. Furthermore, both the multimetric IBI analyses and the RIVPACS-type models produced effective separation of the reference sites from the impaired sites for all field/lab methodologies. These results suggest that alternative methodologies are interchangeable and could complement one another. Thus, the decisions among methods may hinge on objectives, costs, interpretability, and ease of use rather than ability to detect impairment.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly