Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

The Implications of Unregulated Pesticide Run-off on Seafood in Agricultural Catchments (#82)

Kirsten Benkendorff 1 , Endang Jamal 2 , Peter Butcherine 1 , Amanda Reichelt-Brushett 2
  1. Southern Cross University, Coffs Harbour, NSW, Australia
  2. Science and Engineering, Southern Cross University, Lismore, NSW, Australia

Pesticide use in intensive agricultural catchments is a major threat to the health of aquatic ecosystems. Whilst the impact of pesticides on non-target terrestrial and freshwater invertebrates has been well established, the potential for seafood species to be exposed to water soluble pesticides in estuarine environments has rarely been considered. Our ecotoxicology studies confirm that neonicotinoid insecticides can be toxic to prawns and have sublethal impacts on oysters at environmental concentrations. Furthermore, exposure to pesticides can pose a risk to seafood consumers, as some can be uptaken and bioaccumulate in the flesh. Most pesticides do not currently have maximum allowable residue limits set for seafood, and concerningly none of the food safety regulations consider the cumulative concentration of multiple different types of pesticides. We found have found at least 9 pesticides in run-off from hothouses and blueberry farms. A separate field study in a mixed agricultural catchment, dominated by sugar-cane, detected 13 pesticides in oysters, with mixtures of 7-11 pesticides in individual samples. The synergistic interactions from multiple pesticides on seafood health and safety must be considered in future studies, along with improved management to reduce the chance of agriculture pesticides entering the marine food chain.