Oral Presentation SETAC Asia-Pacific Virtual Conference 2022

Pesticide occurrence in the Richmond River estuary, New South Wales, Australia: Comparative method of assessment (#62)

Endang Ms. Jamal 1 2 , Megan Dr. Gillmore 3 , Amanda Prof. Reichelt-Brushett 1 , Kirsten Prof. Benkendorff 1
  1. Southern Cross University, Lismore, NEW SOUTH WALES, Australia
  2. Pattimura University, Faculty of Fisheries and Marine Science, Ambon/Maluku, Indonesia
  3. Department of Planning and Environment, Sydney, NSW, Australia

Monitoring pesticide runoff in the aquatic environment is ecologically important. Efficient methods are required to detect the wide range of possible pesticides that enter estuaries from the surrounding catchments. Here, we investigate the occurrence of pesticides in the Richmond River estuary, New South Wales, Australia, and compare the effectiveness of using oysters and passive samplers (Chemcatcher®) against a conventional sampling technique (grab sampling). Samples were collected from six sites during two separate sampling periods: from January to March 2020 (x composite grab samples and oyster collections) and from February to March 2021 (x composite grab samples and Chemcatcher® deployment). Samples were analysed for 173 pesticide analytes, including insecticides, herbicides, and fungicides. A total of 21 pesticide compounds were detected across all the samples. The number of pesticide compounds detected in the 2020 sampling was higher in oyster samples (13 compounds, 7-11 types per sample) than in grab water samples (6 compounds, 2-5 types per sample). In 2021, Chemcatcher® detected more pesticides in water (10 compounds, 3-7 types per sample) than grab samplers (5 compounds, 2-4 types per sample). Herbicides were the most common in water and oysters. Insecticides and fungicides were detected only in oysters and Chemcatcher®. Herbicide propazine and picloram were only recorded in grab water samplers. Fungicides were recorded at the highest concentration of all pesticide compounds; with up to 20 ng/g, fosetyl Al in oysters and up to 410±14 µg/sampler, diphenylamine in Chemcatchers®. Overall, the use of oysters and Chemcatchers® expanded our understanding of the pesticide inputs to the Richmond River estuary and their utility to provide complementary data for comprehensive monitoring of pesticides in estuarine environments was demonstrated.

  1. Novic, A. J., O’Brien, D. S., Kaserzon, S. L., Hawker, D. W., Lewis, S. E. and Mueller, J. F. (2017). Monitoring herbicide concentrations and loads during a flood event: a comparison of grab sampling with passive sampling. Environmental Science Technology, 51(7), 3880-3891. doi:https://doi.org/10.1021/acs.est.6b02858 Warne, M. S. J., Smith, R. A. and Turner, R. D. R. (2020). Analysis of pesticide mixtures discharged to the lagoon of the Great Barrier Reef, Australia. Environmental Pollution, 265, 114088. doi:https://doi.org/10.1016/j.envpol.2020.114088