Article

Use of microbenthic algal communities in ecotoxicological tests for the assessment of water quality: the Ter river case study

Univ. de Barcelona
Journal of Applied Phycology (Impact Factor: 2.33). 01/2002; 14:41-48. DOI: 10.1023/A:1015242301451

ABSTRACT The tolerance of microbenthic algal communities to two model toxicants, atrazine and copper, was studied in the Ter river during spring and summer. Artificial substrata were colonised at 9 sites and used to perform short-term (1-4 h) toxicity tests in the laboratory and to obtain photon yield as the ecotoxicological endpoint. The tolerance was lower in spring than in summer for both toxic substances and varied according to the site studied. Copper toxicity was associated with physico-chemical conditions (total suspended solids and water pH) and, especially, with several biomass-related parameters, whereas atrazine toxicity was related to algal abundance and species composition. Temporal and spatial changes in nutrient concentration may alter the biomass and species composition of the communities and thus affect their tolerance to toxic substances. It has to be therefore considered that the environmental characteristics of the river system may determine relevant direct and indirect effects on the algal communities, then affecting their specific ecotoxicological responses. Once this is assumed, the empirical expressions obtained on calculating EC50 and EC10 can be used to predict the community-level transient effects of toxic exposures.

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