Pesticide contamination in water and sediment of the aquatic systems of The Natural Park of the Albufera of Valencia (Spain) during the rice cultivation period.

Abstract The Natural Park of the Albufera (Valencia, Spain) is a Mediterranean wetland where rice cultivation dominates the agricultural activity. The purpose of this study was to offer broader information about the current state of the wetland assessing the contamination by pesticides in four aquatic habitats during the rice cultivation period in 2016. Liquid chromatography with tandem mass spectrometer (UHPLC-MS/MS) was used to determine the pesticides in water and sediment samples from the rice fields, Lake Albufera and irrigation and outlet channels. 21 pesticides were detected in our samples (seven already forbidden by European legislation). Higher values than 10000 ng L-1 of accumulated pesticides had been observed in the water samples of the midterm of the cultivation period (July). The sediment samples presented values ten times lower than the water samples. The habitat showed significant differences in the concentrations of the water and sediment samples (Two-way Permanova, p 1). The data provided in this work should show concern about the impact of pesticides in Mediterranean systems subjugated to agricultural pressure.