AIMS, in collaboration with The Clean Ocean Foundation, has completed this proof-of-concept study to facilitate further sampling of microplastics in the Southern Ocean (a joint collaborative initiative involving the Australian Institute of Marine Science (AIMS), the Integrated Marine Observing System (IMOS) and solo yachtswoman Lisa Blair). In this project, AIMS trialled density flotation and chemical digestion separation methods to process subsurface seawater samples and retrieve environmental microplastics. This report presents findings from controlled spike recovery tests as well as opportunistic field sampling events of subsurface waters processed with both separation methods. Opportunistic samples were collected along the NSW coastline in December 2021. Given the location of the sampling transects, this report also provides the first spatial baseline information on microplastic contamination in NSW waters adjacent to estuary outflows and urban outfalls. After trialling both separation methods, microplastics retrieved from the NSW samples were physically and chemically characterized used stereomicroscopy and spectroscopy, respectively. No statistical analysis were performed due to the low number of replicates. Results showed repeated chemical digestion employing potassium hydroxide solutions was most effective at microplastic recovery. Microplastics were retrieved from each of the eight samples collected in NSW subsurface seawaters, with polyethylene and polyester fibres being the most prevalent polymer types detected. The highest numbers of microplastics were recorded adjcent to the estuary outflows and urban outfalls present within the sampling area. Overall, the sampling and processing protocols developed here are allowing for the extension of the spatial coverage of microplastic data in seawaters.\n
Maintenance and Update Frequency: notPlanned
Statement: Data quality was assured using the following publications and SOPs:\n 1. Sample collection was conducted using a microplastic sampler similar to that used by Tanhua et al., 2020\n 2. Sample processing was conducted following the SOPs: SOP_SF_T070_2, SOP_SF_T072_1, and SOP_SF_T0565_1 (AIMS internal documents)\n 3. Extraneous microplastic contamination was controlled following the SOP SF_T064_2\n 4. Extraneous microplastic contamination was identified and characterized following Norén, 2007, Hidalgo-Ruz et al., 2012, Kroon et al. 2018a,b, Santana et al., 2022\n 5. Confirmed microplastics were physically and chemically characterized following the SOPs: SOP SF-T075_1, SOP SF-T076_1, and SOP BAF-I078_5\n References: \n Hidalgo-Ruz, V., Gutow, L., Thompson, R. C., and Thiel, M. (2012). Microplastics in the marine environment: a review of the methods used for identification and quantification. Environ. Sci. Technol. 46, 3060–3075. doi: 10.1021/es2031505\n Kroon, F., Motti, C., Talbot, S., Sobral, P., and Puotinen, M. (2018). A workflow for improving estimates of microplastic contamination in marine waters: a case study from North-Western Australia. Environ. Pollut. 238, 26–38. doi: 10.1016/j.envpol.2018.03.010\n Kroon, F. J., Motti, C. E., Jensen, L. H., and Berry, K. L. E. (2018). Classification of marine microdebris: a review and case study on fish from the Great Barrier Reef, Australia. Sci. Rep. 8:16422. doi: 10.1038/s41598-018-34590-6\n Norén, F. (2007). Small plastic particles in Coastal Swedish waters. KIMO Sweden 11, 1–11.\n Santana MFM, Kroon FJ, van Herwerden L, Vamvounis G, Motti CA. An assessment workflow to recover microplastics from complex biological matrices. Marine Pollution Bulletin 2022; 179: 113676. doi: https://doi.org/10.1016/j.marpolbul.2022.113676\n Tanhua T, Gutekunst SB, Biastoch A. A near-synoptic survey of ocean microplastic concentration along an around-the-world sailing race. PLoS One 2020; 15: e0243203. doi: 10.1371/journal.pone.0243203\n
Australian Institute of Marine Science (AIMS)
Integrated Marine Observing System (IMOS), Australia.
Australia’s Integrated Marine Observing System (IMOS) is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent.
Clean Ocean Foundation, Australia.