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A PILOT STUDY COMPARING TWO BENTHIC MACROINVERTEBRATE COLLECTION METHODS FOR BIOASSESSMENT OF WADEABLE STREAMS
Citation:
Klemm, D J., P. A. Lewis, W T. Thoeny, AND F A. Fulk. A PILOT STUDY COMPARING TWO BENTHIC MACROINVERTEBRATE COLLECTION METHODS FOR BIOASSESSMENT OF WADEABLE STREAMS. Presented at Society of Environmental Toxicology and Chemistry, Salt Lake City, UT, November 18-22, 2002.
Impact/Purpose:
The purpose of this research project is to provide methods, tools and guidance to Regions, States and Tribes to support the TMDL program. This research will investigate new measurement methods and models to link stressors to biological responses and will use existing data and knowledge to develop strategies to determine the causes of biological impairment in rivers and streams. Research will be performed across multiple spatial scales, site, subwatershed, watershed, basin, ecoregion and regional/state.
Description:
This study compared the results of collecting and analyzing macroinvertebrate data using a composite versus a three single sample method. It was conducted as part of the Environmental Monitoring and Assessment Program (EMAP) Indicator Development Project of the U.S. Environmental Protection Agency. Data were collected from four sites on Mill Creek, which flows through the industrial heart of Cincinnati, Ohio, and one reference site on nearby Tanners Creek in southeastern Indiana. Samples were collected from nine transects and composited. Riffle/Run and Pool/Glide samples were composited separately and processed using U.S. EPA's EMAP macroinvertebrate sampling and laboratory protocols. A single sample was collected at three randomly selected transects of the nine, but the three samples were processed in the laboratory as separate samples (not composited). Macroinvertebrate samples were analyzed using the Stream Benthos Integrity Index (SBII), consisting of 10 metrics. The data indicated that similar results were obtained using either sampling method. The SBII scores for the sites were ranked in the same order using either method, and these rankings were according to expectations based on chemical and physical conditions. It was concluded from the data that collecting and processing three random single samples from each stream reach gave similar SBII scores as the composite samples. The three single sample method also allows a measure of repeatability which gave more confidence in the results of the sampling data. The collection effort was 1/3 that required for the composite method and in this study the sorting and identification effort was also considerably reduced. It is recommended that additional studies be conducted on other gradient streams in other ecoregions to determine if the three sample method might reduce effort and expense in bioassessment studies elsewhere.