15:30 〜 17:00
[MIS17-P10] Microplastic contamination in three sinks at the benthic zone: A case study of Tokyo Bay
キーワード：Small Microplastics (SMPs), Polymers, Macrobenthic fauna, Sediments, Feeding modes, Near-bottom water
The ubiquitous nature of plastic has been a major concern to our oceans’ health, with citations of these compounds recorded in the most remote ocean areas, most of which are microplastics. Their persistent nature in the marine environment has resulted in their fragmentation into smaller particles not visible to the naked eye. These small microplastics (SMPs, <300 µm), apart from marking the Anthropocene era, threaten marine life as they are susceptible to ingestion by organisms that play a vital role in secondary production at the seabed.
Samples from near-bottom water, sediments, and macrofauna were collected from four stations in Tokyo Bay using a mud collector. The different sink samples were prepared separately and analyzed for SMPs using a micro-Fourier transform infrared (µFTIR). Polymer and size identification were performed using KnowItAll and ImageJ, respectively.
Water samples contained 221.5±181.5 pcs L-1, sediments had 16.6±8.4 pcs g-1 DW, and macrofauna was 3.8±3.7 pcs ind-1; no significant difference in concentrations in both water and sediments was observed among the stations. The SMPs particle sizes were generally smaller; however, there was a shift in the peak size range from 41-60 for water samples to 31-50 µm for sediment samples, while macrofauna peaked between 41-50 µm. Polyethylene (PE) and Copolymer dominated polymer abundances in the water and sediment samples, while PE and Polyamide (PA) were the dominant polymers ingested by macrobenthic fauna. Other polymer types, including Polypropylene (PP), polyester (PES), Poly Ethylene Terephthalate (PET), and Polyvinyl chloride (PVC), Polystyrene (PS), were also recorded but in low abundances.
Correlation analysis indicated a significantly high positive correlation between the polymers recorded in water and the sediments from the same station. SMP concentrations in macrofauna based on feeding modes indicated a higher concentration of SMPs ingestion by deposit feeders, followed by predators, the least SMPs concentration ingested was observed in filter feeders. The results indicate the extensive pollution level in marine environments and their concentrations in different sinks, which may help inform the decision-making processes towards addressing marine plastic pollution.
Samples from near-bottom water, sediments, and macrofauna were collected from four stations in Tokyo Bay using a mud collector. The different sink samples were prepared separately and analyzed for SMPs using a micro-Fourier transform infrared (µFTIR). Polymer and size identification were performed using KnowItAll and ImageJ, respectively.
Water samples contained 221.5±181.5 pcs L-1, sediments had 16.6±8.4 pcs g-1 DW, and macrofauna was 3.8±3.7 pcs ind-1; no significant difference in concentrations in both water and sediments was observed among the stations. The SMPs particle sizes were generally smaller; however, there was a shift in the peak size range from 41-60 for water samples to 31-50 µm for sediment samples, while macrofauna peaked between 41-50 µm. Polyethylene (PE) and Copolymer dominated polymer abundances in the water and sediment samples, while PE and Polyamide (PA) were the dominant polymers ingested by macrobenthic fauna. Other polymer types, including Polypropylene (PP), polyester (PES), Poly Ethylene Terephthalate (PET), and Polyvinyl chloride (PVC), Polystyrene (PS), were also recorded but in low abundances.
Correlation analysis indicated a significantly high positive correlation between the polymers recorded in water and the sediments from the same station. SMP concentrations in macrofauna based on feeding modes indicated a higher concentration of SMPs ingestion by deposit feeders, followed by predators, the least SMPs concentration ingested was observed in filter feeders. The results indicate the extensive pollution level in marine environments and their concentrations in different sinks, which may help inform the decision-making processes towards addressing marine plastic pollution.