Pesticides in a temperate coastal lagoon in southwest Europe (Ria de Aveiro, Portugal) – Risk assessment and acute assays with Artemia and Daphnia

Abstract

The Ria de Aveiro lagoon has been considered one of the most important Southern European long-term monitoring sites (LTER-site) concerning climate change and anthropogenic pollution. Nevertheless, studies concerning pesticide contamination herein are few and mostly outdated. Here, 56 pesticides dissolved in the aqueous phase (DAP) and suspended particulate matter (SPM) were examined to fill the knowledge gap, considering the hydrophobic nature of most evaluated compounds. Water samples were taken seasonally from eight sites, and both DAP and SPM fractions were analysed by gas-chromatography-mass spectrometry. The annual average concentrations of fungicides, herbicides and insecticides were ≈57 ng/L, ≈409 ng/L and ≈1058 ng/L in DAP and ≈7 μg/g, ≈28 μg/g and ≈67 μg/g in SPM. These pesticides and the excessive phosphate concentrations suggest that the lagoon's water quality may be hazardous to biota and humans. Invertebrates were identified as the most threatened trophic level using deterministic risk assessment, with chlorpyriphos and chlorfenvinphos being the primary culprits. Acute experiments with Artemia and Daphnia supported the suppositions.