Details

Autor(en) / Beteiligte

• Dai, Zhenfei
• Zhang, Haibo
• Zhou, Qian
• Tian, Yuan
• Chen, Tao
• Tu, Chen
• Fu, Chuancheng
• Luo, Yongming

Titel

Occurrence of microplastics in the water column and sediment in an inland sea affected by intensive anthropogenic activities

Ist Teil von

• Environmental pollution (1987), 2018-11, Vol.242 (Pt B), p.1557-1565

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• Microplastics may lose buoyancy and occur in deeper waters and ultimately sink to the sediment and this may threaten plankton inhabiting in various water layers and benthic organisms. Here, we conduct the first survey on microplastics in the water column and corresponding sediment in addition to the surface water in the Bohai Sea. A total of 20 stations covering whole Bohai Sea were selected, which included 6 stations specified for water column studying. Seawater was sampled every 5 m, with maximal depth of 30 m in the water column using Niskin bottles coupled with a ship-based conductivity, temperature and depth sensor (CTD) system and surface sediment samples were collected using box corer. The results indicated that higher microplastic levels accumulated at a depth range of 5–15 m in the water column in some stations, suggesting the surface water survey was not sufficient to reflect microplastics loading in a water body. Fibers predominated microplastic types in both seawater and sediment of the Bohai Sea, which accounted for 75%–96.4% of the total microplastics. However the relatively proportion of the fibers in the deeper water layers and sediment was lower than that in the surface water. Microplastic shapes are more diverse in the sediment than in the seawater in general. The microplastic sizes changed with depth in the water column and the proportion of the size-fraction < 300 μm increased with depth, probably as a result of rapid biofouling on the small microplastics due to their higher specific surface area. Such depth distribution also implied that sampling with manta net (>330 μm) that commonly used in the oceanographic survey might underestimate microplastics abundance in the water column. Further studies are recommended to focus on the sinking behavior of microplastics and their effects on marine organisms. [Display omitted] •Microplastics levels in the surface sea were closely related with human activities.•A higher amount of microplastics accumulated in the depth of 5–15 m in the Bohai Sea.•Micropalstics with size <300 μm tended to sinking and presenting in the deeper water.•Microplastics abundance was not consistent between water and corresponding sediment. Substantial amount of microplastics accumulated in the deeper water rather than the surface water of the Baohai Sea.