Contamination of sea surface water offshore the Tokai region and Tokyo Bay in Japan by small microplastics

Haodong Xu; Haruka Nakano; Tadashi Tokai; Tadashi Miyazaki; Hiroaki Hamada; Hisayuki Arakawa

doi:10.1016/j.marpolbul.2022.114245

Contamination of sea surface water offshore the Tokai region and Tokyo Bay in Japan by small microplastics

Mar Pollut Bull. 2022 Dec;185(Pt A):114245. doi: 10.1016/j.marpolbul.2022.114245. Epub 2022 Oct 21.

Authors

Haodong Xu¹, Haruka Nakano², Tadashi Tokai³, Tadashi Miyazaki⁴, Hiroaki Hamada⁵, Hisayuki Arakawa⁶

Affiliations

¹ Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: Carraway_Xu1997@hotmail.com.
² Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: nakano.hrk@riam.kyushu-u.ac.jp.
³ Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: tokai@kaiyodai.ac.jp.
⁴ Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: miyany@kaiyodai.ac.jp.
⁵ Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: hiroaki@kaiyodai.ac.jp.
⁶ Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address: arakawa@kaiyodai.ac.jp.

PMID: 36279726
DOI: 10.1016/j.marpolbul.2022.114245

Abstract

A nested double neuston net was prepared and used to collect samples from the surface of coastal waters around Japan to obtain information about the properties of both small microplastics (SMPs; <350 μm) and large microplastics (LMPs; >350 μm). The SMP concentrations ranged from 1000 to 5900 pieces m^-3 in the open ocean and averaged approximately 3000 pieces m^-3 in the inner part of Tokyo Bay. The SMP concentrations were around 20-60 times greater than the LMP concentrations. By analyzing the seawater, we obtained a microplastic size distribution that spanned 50-5000 μm. The LMPs mainly comprised packaging-related plastics, such as polyethylene (PE) and polypropylene, while the SMPs were dominated by paint-related plastics. SMPs derived from packaging materials (e.g., PE) may have gradually sank down from the sea surface when they were smaller than 600 μm.

Keywords: Concentration; Neuston net; Sea surface; Size distribution; Small microplastics.

MeSH terms

Bays
Environmental Monitoring
Japan
Microplastics*
Plastics
Polyethylene / analysis
Seawater
Tokyo
Water
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Water Pollutants, Chemical
Polyethylene
Water