Physiological and Biochemical Effects of Insecticides on Catla catla from Freshwater Ecosystems: A Biomarker-Based Monitoring System for Yeldari Reservoir, Maharashtra

Abstract

Agricultural insecticides reach freshwater reservoirs through runoff, drainage, leaching and accidental discharge, and fish are exposed continuously through gills, skin and diet. Catla catla (Hamilton), an Indian major carp of high economic and ecological value, is a suitable sentinel species for such contamination. This paper reviews the physiological, haematological, biochemical, oxidative and histopathological responses of C. catla to organophosphate, organochlorine, pyrethroid and neonicotinoid insecticides, and identifies the gaps that limit their use in field risk assessment. Building on this evidence, we present a methodology and a proposed six-module system for Yeldari Reservoir, a hydroelectric and irrigation reservoir on the Purna River, that links catchment pesticide-use surveys, seasonal field monitoring, laboratory bioassays, a multi-biomarker panel, integrated data analysis (Integrated Biomarker Response and risk quotient) and decision support. The approach is intended to show whether agricultural insecticides cause measurable physiological stress in the reservoir’s C. catla population, and to convert that evidence into management advice.