5:15 PM - 6:45 PM
[MIS09-P04] Seafloor marine litter in the Gulf of Thailand
Keywords:Plastic, Gulf of Thailand, Seafloor marine litter
In recent years, plastic pollution has emerged as a pressing global concern, impacting ecosystems worldwide. Despite uncertainties surrounding plastic emissions, addressing plastic pollution remains imperative, particularly in Southeast Asian nations where plastic pollution is significant. To shed light on this issue, collaborative efforts between Thai and Japanese researchers were undertaken to conduct a comprehensive survey of marine litter in the Gulf of Thailand. In this presentation, the results of marine benthic litter will be discussed.
A comprehensive survey of marine debris was conducted aboard the Southeast Asian Fisheries Development Center (SEAFDEC) research vessel SEAFDEC2 from October 15 to October 22. Twelve observation points were selected within the Gulf of Thailand (GoT). At each observation point, a bottom trawl net was operated at a speed of 3 knots for one hour. Samples collected after trawling were classified onboard as biological material or marine debris. The samples were then brought to the laboratory under freezing conditions for further analysis. Once in the laboratory, the marine debris was classified by, color (15 categories, three for Non-pigmented colors: Yellowish, Clear, and Opaque, and 12 for pigmented ones: White, Gray, Black, Brown, Green, Blue, Red, Pink, Purple, Yellow, Orange, and Mixed color), and the dry weight and maximum length were recorded. Each item was categorized into seven main material categories (Plastic, Rubber, Paper, Cloth, Glass, Metal, and Others) and 16 litter types (Plastic bags, Plastic food packages, Plastic bottles, Plastic containers, Plastic sheets, Strings, Ropes, Fishing gear, Foamed Plastic, Rubber, Paper, Cloth, Glass, Metal, Other artificial material, Natural matter). Each litter's materials were identified using the attenuated total reflection method and transmission mode for Fourier transform infrared spectrometry (IRTracer-100, SHIMADZU). Also, a carbonyl index, showing the degree of degradation, was calculated using the infrared spectra of litter.
Plastic was the main marine litter type, with fragments of large plastic items, such as fishing gear or sheets, being dominant. Likewise, at most stations, a weight-based comparison also described that plastic litter, especially fishing gear, was predominant in the seafloor of GoT. These results were consistent with previous reports, indicating plastic litter, especially fishing gear, as the main composition of seafloor litter.
Furthermore, the expired or production dates on several plastic food packages (e.g., 23rd April 2023, 3rd August 2023) described that the plastic litter was recently emitted into the environment. Also, the characteristics of the packages, including their languages (e.g., Thai and Chinese), indicate that these products have been consumed in those respective countries and subsequently released into the environment. This underscores the need for increased efforts in raising public awareness to achieve the Sustainable Development Goals (SDGs). During the presentation, we will report on the characteristics of marine litter collected in the GoT, as well as discuss the distribution and degree of degradation of marine litter on the seafloor of the GoT.
A comprehensive survey of marine debris was conducted aboard the Southeast Asian Fisheries Development Center (SEAFDEC) research vessel SEAFDEC2 from October 15 to October 22. Twelve observation points were selected within the Gulf of Thailand (GoT). At each observation point, a bottom trawl net was operated at a speed of 3 knots for one hour. Samples collected after trawling were classified onboard as biological material or marine debris. The samples were then brought to the laboratory under freezing conditions for further analysis. Once in the laboratory, the marine debris was classified by, color (15 categories, three for Non-pigmented colors: Yellowish, Clear, and Opaque, and 12 for pigmented ones: White, Gray, Black, Brown, Green, Blue, Red, Pink, Purple, Yellow, Orange, and Mixed color), and the dry weight and maximum length were recorded. Each item was categorized into seven main material categories (Plastic, Rubber, Paper, Cloth, Glass, Metal, and Others) and 16 litter types (Plastic bags, Plastic food packages, Plastic bottles, Plastic containers, Plastic sheets, Strings, Ropes, Fishing gear, Foamed Plastic, Rubber, Paper, Cloth, Glass, Metal, Other artificial material, Natural matter). Each litter's materials were identified using the attenuated total reflection method and transmission mode for Fourier transform infrared spectrometry (IRTracer-100, SHIMADZU). Also, a carbonyl index, showing the degree of degradation, was calculated using the infrared spectra of litter.
Plastic was the main marine litter type, with fragments of large plastic items, such as fishing gear or sheets, being dominant. Likewise, at most stations, a weight-based comparison also described that plastic litter, especially fishing gear, was predominant in the seafloor of GoT. These results were consistent with previous reports, indicating plastic litter, especially fishing gear, as the main composition of seafloor litter.
Furthermore, the expired or production dates on several plastic food packages (e.g., 23rd April 2023, 3rd August 2023) described that the plastic litter was recently emitted into the environment. Also, the characteristics of the packages, including their languages (e.g., Thai and Chinese), indicate that these products have been consumed in those respective countries and subsequently released into the environment. This underscores the need for increased efforts in raising public awareness to achieve the Sustainable Development Goals (SDGs). During the presentation, we will report on the characteristics of marine litter collected in the GoT, as well as discuss the distribution and degree of degradation of marine litter on the seafloor of the GoT.