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.

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.