Evaluation of the occurrence and fate of pesticides in a typical Mediterranean delta ecosystem (Ebro River Delta) and risk assessment for aquatic organisms

Delta ecosystems are areas of high ecologic and economic values, where wildlife commonly shares the territory with intensive agricultural activities, particularly, rice cultivation seafood production. This work aimed at evaluating occurrence a wide spectrum pesticides transformation products in water irrigation drainage channels Ebro River (NE Spain) during main rice-growing season, when pesticide application is its peak. Furthermore, impact that these contaminants may have on local production activities was assessed. A total 35 pesticides, mainly associated cultivation, out 66 analyzed were detected. Bentazone, propanil, MCPA, acetamiprid, triallate found μg/L level. Cybutryne, despite being banned European Union, measured for first time area concentrations above environmental quality standard (11–49 ng/L). Sixteen additional also detected trace levels, likely due to their desorption from soil sediment particles. Despite dilution discharged into bay, this study demonstrates use important effects cause serious hazard aquatic non-target organisms, although other factors such as temperature salinity play relevant role. cybutryne, dicofol, imidacloprid, propanil pose moderate risk organisms concentration levels season. The co-occurrence result all sampling locations. finding EU Watch List insecticides imidacloprid acetamiprid maximum acceptable method detection limit calls control revision legal status.