title: Influence of the organophosphorus insecticide phosphamidon on lentic water.
abstract: The inland freshwater resources are being increasingly subjected to heavy stress as a result of indiscriminate dumping of industrial wastes, domestic sewage and agricultural run-off causing deterioration of the water quality and adverse impact on aquatic biota. Pesticides drained to the aquatic environment are primarily of agricultural origin. Phosphamidon (widely used organophosphate pesticide in paddy field) significantly reduced dissolved oxygen (DO) at 1.8 mg/l exposure and reduced alkalinity at 0.9 and 1.8 mg/l. Hardness also reduced gradually but not significantly. Free carbondioxide was increased significantly at 1.8 mg/l of the insecticide compared to control. The insecticide had no influence on pH and temperature. There was maximum reduction of phytoplankton and zooplankton population at 1.8 mg/l of phosphamidon. Though gradual reduction of plankton community was also noticed at different lower concentrations of pesticides but in case of phytoplankton an abrupt reduction (about 50% of the control) was observed. The normal behaviour and feeding rate of air breathing teleost, Channa punctatus was also hampered. Therefore, phosphamidon even at low concentrations may create disorders in the aquatic ecosystem.
authors.affiliation: Aquaculture and Limnology Laboratory, Department of Zoology, University of North Bengal-734 430, District Darjeeling, India.
authors.forename: Gopal
authors.initials: G
authors.lastname: Dhar
authors.forename: Sudip
authors.initials: S
authors.lastname: Barat
authors.forename: Kakali Mitra
authors.initials: KM
authors.lastname: Dhar
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D017753:Ecosystem; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007306:Insecticides / Q000633:toxicity*; D009943:Organophosphorus Compounds / Q000633:toxicity*; D010100:Oxygen / Q000378:metabolism; D010707:Phosphamidon / Q000633:toxicity*; D010839:Phytoplankton / Q000187:drug effects / Q000502:physiology; D012722:Sewage / Q000737:chemistry; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects / Q000502:physiology
chemical_list: D007220:Industrial Waste; D007306:Insecticides; D009943:Organophosphorus Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; D010707:Phosphamidon; D010100:Oxygen