You are here:
COMPARISON OF TWO MACROINVERTEBRATE COLLECTION METHODS FOR BIOASSESSMENT OF WADEABLE STREAMS
Citation:
Klemm, D J., P. A. Lewis, W T. Thoeny, AND F A. Fulk. COMPARISON OF TWO MACROINVERTEBRATE COLLECTION METHODS FOR BIOASSESSMENT OF WADEABLE STREAMS. Presented at North American Benthological Society, La Crosse, WI, June 3-8, 2001.
Impact/Purpose:
The goal of this research is to develop methods and indicators that are useful for evaluating the condition of aquatic communities, for assessing the restoration of aquatic communities in response to mitigation and best management practices, and for determining the exposure of aquatic communities to different classes of stressors (i.e., pesticides, sedimentation, habitat alteration).
Description:
The objective of this study was to compare the results of collecting and analyzing macroinvertebrate data using a composite versus a 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 (EPA). Data were collected from four sites on nearby Tanners Creek in Indiana. The composite samples were collected from nine transects and processed using U.S. EPA's EMAP macroinvertebrate sampling and laboratory protocols. The single samples were collected one at each of three randomly selected transects, but the three samples were processed in the laboratory as separate samples (not composited). The biological data were analyzed using a Stream Benthos Interity 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. We conclude that collecting and processing three random single samples from each stream reach gave the same SBII score as collecting nine samples and compositing them. The three sample method 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 considerably reduced. We recommend that additional studies be conducted on other types of streams to determine if the three sample method might reduce effort and expense in EMAP studies elsewhere.