Bioassay responses of micro-organisms to sediment elutriates from the St. Lawrence River (Lake St. Louis)

Abstract

A sediment study, involving both chemical and biological analyses, was carried out in the St. Lawrence River near Montreal (Lake St. Louis). About 60 stations were sampled during 1984-85, and the sediments were analyzed for support variables, heavy metals, and organochlorinated compounds. Subsamples were elutriated using a 1 to 4 sediment/water ratio. The resulting elutriates were analyzed for several chemical variables, while toxicity was measured using the Microtox test, algal 4 C assimilation, and lethality/developmental inhibition in cladocerans, rotifers, and nematodes. The results showed a great variety of responses and sensitivity, and correlations between the tests were non-significant. In terms of toxic responses, the algal and Microtox tests were the most sensitive. Toxic responses could not be explained in simple terms of contaminant concentrations. Therefore, the chemistry of elutriates is not predictive of the toxic potential of contaminated sediments. Biotests can give an insight into the hazard assessment of sediments, but no single test will be sufficient; the use of a battery of standardized biotests, representing different levels of organization/food chain, including representative natural species, is highly recommended.

Rotifers in ecotoxicology: a review

“…In recent years, several workers have used B. calyciflorus and B. plicatilis for various types of toxicity assessments . The toxicity of sediment pore waters and elutriates of contaminated sediments originating from the St. Lawrence River have been evaluated with B. calyciflorus neonates obtained from cultures Sloterdijk et al ., 1989) . Moses & Wade (1992 a&b) have assessed the potential use of the cyst-based B .…”

Comparative ecotoxicity of suspended sediment in the lower Rhone River using algal fractionation, Microtox® and Daphnia magna bioassays

“…It is recognized that ecotoxicological testing needs to be based on standard test organisms and to be supplemented by the use of some ambient bioassay. Furthermore a battery of tests should be used in order to ensure that the 'no effect level' in one test will also be discriminated at several trophic levels (Nebecker et al, 1984;Cairns & Pratt, 1989;Dutka et al, 1989;Sloterdijk et al, 1989;Giesy & Hoke, 1989). In this paper we concentrate on the ecotoxicity associated with suspended sediments of the Rhone River as determined by three acute bioassay procedures.…”

Ecotoxicological Assessment and Effects of Physicochemical Factors on Biofilm Development in Groundwater Conditions

“…SMPs Accumulation and Ecotoxicological Assessment. The green algae ( S. capricornutum ) and Microtox ( V. fischeri ) tests are known to be very sensitive, and they are widely used for water toxicity assessment ( , ). The algal growth inhibition results, when submitted to non diluted groundwater samples at different period of the microbial develop ment, are shown in Figure .…”