[M-IS17] 地球科学としての海洋プラスチック

[MIS17-P12] The occurrence of microplastics in Russell’s snapper (Lutjanus russellii) and the potential of trophic transfer in their food web

*Suppakarn - Jandang¹、Siriluk - Prachumwong²、Nakano - Haruka¹、Maria Belen Alfonso¹、Suchana - Chavanich³、Voranop - Viyakarn³、Wanlada - Klangnurak² (1.Research Institute for Applied Mechanics, Center for Ocean Plastic Studies, Kyushu University, Japan、2.Department of Animal Production Technology and Fishery, Faculty of Agricultural Technology, King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand 、3.Aquatic Resources Research Institute, Chulalongkorn University, Bangkok, Thailand)

キーワード：Microplastic, Fish, Food web, Trophic level

The contamination of microplastics (MPs) in marine environments is currently experiencing an emergency level, especially when it enters the human food chain by ingestion. A Lutjanidae or snapper is one of the most important food fish for humans due to its delicacy and nutritional value. Although several studies have found the presence of MPs across Lutjanidae species worldwide, the trophic transfer route of MPs via their food web is not well established. The aim of this study was to investigate the MPs abundance, characteristics and polymer type within the stomach of Russell’s snapper (Lutjanus rusellii) and their prey. The fish sample and prey were collected from the Chumphon coast, in the lower Gulf of Thailand. The index of relative importance (IRI) showed that the most important food item were zooplankton, crustaceans and fishes. We observed that the major MPs type are fiber and fragment, accounting for all MPs present in both fish and prey samples. Also, numerous MPs polymer types were identified by FT-IR. Based on the scientific evidence, our results reveal that MPs can be ingested by the lower trophic levels organisms such as plankton and small fishes. Therefore, the distribution and accumulation of MPs through the food web is expected to lead to greater exposure for commercial fish species (higher trophic level) as well as human populations.