tailieunhanh - The effect of tannery effluent on the colonization rate of plankters: A microcosm study

The present study describes a multispecies toxicity test that uses community level responses of plankton samples from a natural lake using polyurythane foam (PF) as artificial substrate. These substrates were suspended and left for a period of 14 days. | Turk J Biol 27 (2003) 163-170 © TÜB‹TAK The Effect of Tannery Effluent on the Colonization Rate of Plankters: A Microcosm Study Yalavarthi Naga KOTESWARI, Ravichandran RAMANIBAI Department of Zoology, Unit of Biomonitoring Management, University of Madras, Guindy Campus, Chennai 600 025, INDIA Received: Abstract: The present study describes a multispecies toxicity test that uses community level responses of plankton samples from a natural lake using polyurythane foam (PF) as artificial substrate. These substrates were suspended and left for a period of 14 days. Colonized substrates were then placed in a series of microcosms dosed with a gradient of tannery effluent from 1 to 15% concentration. The species composition and abundance of the planktonic communities in PF substrate with the exposure of 4 different concentration of tannery effluent (1%, 3%, 5% and 15%) were assessed on days 1, 3, 7, 14, 21 and 28. Species diversity and abundance in colonized PF substrate showed a significant difference in different effluent treatments. Similarly, an inverse relationship was noted between effluent dosage and species surviving in source PF substrate at the end of the experiment period. Key Words: Microcosm, toxicity, colonization rate, sensitivity, endpoints Introduction The direct discharge of effluents from industries and municipal wastewater treatment plants into bodies of water has become a growing environmental problem. Most of these wastewaters are extremely complex mixtures containing inorganic and organic compounds (1). The best way to analyse risk assessment has been to develop biological test systems, which, combined with chemical analysis, can be useful for evaluating aquatic assessments and establishing relevant water quality criteria (2). In order to assess the toxicity of anthropogenic chemicals, single species toxicity tests often conducted. These tests are much easier to perform and often their results are easier to interpret (3). In .