Algal benthic population and community from stress insecticide- Endosulfan in laboratory streams

Human activities have resulted in release of a large of toxic contaminants into aquatic ecosystems.Aquatic ecosystems face variableexposure to pesticides , especially during flooding which are associated with short bursts of high contaminant concentrations that influence biological systems. An experiment was carried out using indoor experimental channels to assess the long-term effect (20 days) of insecticide on algal communities exposed to Three treatments of insecticide endosulfan (0.25,0.50 and 100 µg L¯¹) and a control .The effects of endosulfan on community biomass were assessed by measuring dry mass, ash-free dry mass (AFDM), chlorophyll a and autotrophic index (AI) factors. In laboratory streams with endosulfan, there was a significant (p <0.05) reduction of chlorophyll a, dry mass and AFDM and increased (AI ), compared to controls with low endosulfan. These observations suggest that biomass of algal community could serve as an indicator of endosulfan pollution.

Keywords:

LABORATORY STREAM , benthic algal , biomass , dry mass , chlorophyll a , AFDM