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Published: 1995

Total Pages: 13

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Describes a project to develop a set of techniques for monitoring & assessment of surface water quality in agricultural regions of southern Ontario, based on benthic invertebrates. The project involved determining the best way to collect appropriate samples, how closely the animals should be identified, and how the results can be interpreted. Each of over 250 sampling sites was visited at least once over 1990-91 and 1993. At each site, the investigators noted the crop(s) grown upstream, the nature of the stream channel & substratum, the dimensions & composition of riparian vegetation, and compiled lists of benthic invertebrates and their percentage composition. Reference & agricultural sites were compared using a variety of summary measures to determine which measure best discriminated among sites. Findings are discussed with regard to the evaluation of the sampling & processing techniques, and indices & interpretative techniques. Part of the study that examined the sensitivity of invertebrate communities to changes in farming practices (conservation versus conventional tillage) is also described. Finally, the procedure developed for the invertebrate monitoring protocol is presented.