南海与周边海域表层塑料颗粒交换的拉格朗日示踪研究

1.热带海洋环境国家重点实验室(中国科学院南海海洋研究所), 广东 广州 510301

2.南方海洋科学与工程广东省实验室(广州), 广东 广州 511458

3.中国科学院大学资源与环境学院, 北京 100049

4.中国科学院大学地球与行星科学学院, 北京 100049

5.澳门科技大学资讯科技学院, 澳门特别行政区 999078

Exchanges of surface plastic particles in the South China Sea through straits using Lagrangian method

MENG Zhao,1,3, LI Ning5, GUAN Yuping,1,2,4, FENG Yang1,2

1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China

2. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China

3. College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China

4. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China

5. Faculty of information Technology, Macau University of Science and Technology, Macao Special Administrative Region 999078, China

 基金资助: 国家自然科学基金项目.  41676021广东省实验室重大专项.  GML2019ZD0306广东省实验室重大专项.  GML2019ZD0303

Corresponding authors: GUAN Yuping. E-mail: guan@scsio.ac.cn

Editor: YIN Bo

Received: 2019-11-20   Revised: 2020-02-24   Online: 2020-09-10

 Fund supported: National Natural Science Foundation of China.  41676021Major Project of Guangdong Province Laboratory.  GML2019ZD0306Major Project of Guangdong Province Laboratory.  GML2019ZD0303

Abstract

Plastics have caused serious pollution in the ocean, and become one of the marine environmental issues of concern to the international marine community. The South China Sea is a major area of marine plastic pollution. The areas around the South China Sea are major sources of plastic pollution, and previous studies have focused on the offshore environment. In this study, we discuss the exchange of plastic particles in the surface of the South China Sea and surrounding waters by ocean circulations. First, the particles were placed at the junction of the South China Sea and its adjacent seas, and were released at the initial time of every season Using Lagrangian particle tracing method, we analyzed the trajectories and final locations of the particles within one year after release. The results show that plastic particles enter the South China Sea mainly through the southern strait. The transport of particles at the same starting point varies a lot with season. During autumn and winter, most particles will enter the South China Sea and Java Sea, and little particles will be transported to the Pacific Ocean. However, only a few particles enter the South China Sea and Java Sea during spring and summer, while most of them are transported to the Pacific Ocean .The South China Sea current is mainly affected by monsoon and has significant seasonal characteristics. This research will help understand the impact of surface plastics around the South China Sea on the plastic pollutant in the South China Sea.

Keywords： plastic ; circulation ; seasonal change ; South China Sea

MENG Zhao, LI Ning, GUAN Yuping, FENG Yang. Exchanges of surface plastic particles in the South China Sea through straits using Lagrangian method. JOURNAL OF TROPICAL OCEANOGRAPHY[J], 2020, 39(5): 109-116 doi:10.11978/2019118

1 数据和方法

1.2 方法

1.2.1 结构

$\frac{\text{d}{{x}_{\text{path}}}\text{(}t\text{,}\ {{x}_{\text{0}}}\text{,}\ {{t}_{\text{0}}}\text{)}}{\text{d}t}\text{=}U\text{ }\!\![\!\!\text{ }{{x}_{\text{path}}}\text{(}t\text{,}\ {{x}_{\text{0}}}\text{,}\ {{t}_{\text{0}}}\text{),}\ t\text{ }\!\!]\!\!\text{ }$

1.2.2 颗粒控制

$({{p}_{x}},{{p}_{y}})=[\frac{({{S}_{y}}-la{{t}_{1}})}{la{{t}_{2}}-la{{t}_{1}}}\times {{n}_{\text{line}}},\frac{({{S}_{x}}-lo{{n}_{1}})}{lo{{n}_{2}}-lo{{n}_{1}}}\times {{n}_{\text{column}}}]$

1.2.3 动态示踪轨迹生成

${{x}_{\text{path}}}(t,{{x}_{0}},{{t}_{0}})={{x}_{0}}+\underset{{{t}_{0}}}{\overset{t}{\mathop \int }}\,u[{{x}_{\text{path}}}(s,{{x}_{0}},{{t}_{0}}),s]\text{d}s$

2 结果与分析

图1

a. 台湾海峡; b. 吕宋海峡; c. 南海与苏禄海交界处一; d. 南海与苏禄海交界处二; e. 加里曼丹岛沿岸; f. 卡里马塔海峡; g. 马六甲海峡; h. 中南半岛沿岸。红色五角星代表颗粒的初始位置点, 蓝色线代表颗粒运动轨迹, 黑色三角形代表颗粒的最终停留点。依据审图号GS(2016)1667底图制作

Fig. 1   Particle transport in spring

图2

a. 台湾海峡; b. 吕宋海峡; c. 南海与苏禄海交界处一; d. 南海与苏禄海交界处二; e. 加里曼丹岛沿岸; f. 卡里马塔海峡; g. 马六甲海峡; h. 中南半岛沿岸。红色五角星代表颗粒的初始位置点, 蓝色线代表颗粒运动轨迹, 黑色三角形代表颗粒的最终停留点。依据审图号GS(2016)1667底图制作

Fig. 2   Particle transport in summer

图3

a. 台湾海峡; b. 吕宋海峡; c 南海与苏禄海交界处一; d. 南海与苏禄海交界处二; e. 加里曼丹岛沿岸; f. 卡里马塔海峡; g. 马六甲海峡; h. 中南半岛沿岸。红色五角星代表颗粒的初始位置点, 蓝色线代表颗粒运动轨迹, 黑色三角形代表颗粒的最终停留点。依据审图号GS(2016)1667底图制作

Fig. 3   Particle transport in autumn

图4

a: 台湾海峡; b: 吕宋海峡; c: 南海与苏禄海交界处一; d: 南海与苏禄海交界处二; e: 加里曼丹岛沿岸; f: 卡里马塔海峡; g: 马六甲海峡; h: 中南半岛沿岸。红色五角星代表颗粒的初始位置点, 蓝色线代表颗粒运动轨迹, 黑色三角形代表颗粒的最终停留点。依据审图号GS(2016)1667底图制作

Fig. 4   Particle transport in winter

3 结果与讨论

图5

Fig. 5   Mean currents in spring (a), summer (b), autumn (c), and winter (d) (Data Source: OGCM for the Earth Simulator, OFES)

参考文献 原文顺序 文献年度倒序 文中引用次数倒序 被引期刊影响因子

BJORNDAL K A, BOLTEN A B, LAGUEUX C J, 1994.

Ingestion of marine debris by juvenile sea turtles in coastal Florida habitats

[J]. Marine Pollution Bulletin, 28(3):154-158.

CÓZAR A, ECHEVARRÍA F, GONZÁLEZ-GORDILLO J I, et al, 2014.

Plastic debris in the open ocean

[J]. Proceedings of the National Academy of Sciences of the United States of America, 111(28):10239-10244.

There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.

CÓZAR A, MARTÍ E, DUARTE C M, et al, 2017.

The Arctic Ocean as a dead end for floating plastics in the North Atlantic branch of the Thermohaline Circulation

URL     PMID:28439534

CHIBA S, SAITO H, FLETCHER R, et al, 2018.

Human footprint in the abyss: 30 year records of deep-sea plastic debris

[J]. Marine Policy, 96:204-212.

ERIKSEN M, LEBRETON L C M, CARSON H S, et al, 2014.

Plastic pollution in the World’s oceans: more than 5 trillion plastic pieces weighing over 250000 Tons Afloat at Sea

[J]. PLoS ONE, 9(12):e111913.

Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007-2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680) and visual survey transects of large plastic debris (N = 891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic <4.75 mm and meso- and macroplastic >4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove <4.75 mm plastic particles from the ocean surface.

GEYER R, JAMBECK J R, LAW K L, 2017.

Production, use, and fate of all plastics ever made

URL     PMID:28776036

HAND E, 2014.

Arctic sea ice traps floating plastic

[J]. Science, 344(6187):985.

HU JIANYU, KAWAMURA H, HONG HUASHENG, et al, 2000.

A review on the currents in the South China Sea: seasonal circulation, South China Sea warm current and Kuroshio intrusion

[J]. Journal of Oceanography, 56(6):607-624.

HURLEY R, WOODWARD J, ROTHWELL J J, 2018.

Microplastic contamination of river beds significantly reduced by catchment-wide flooding

[J]. Nature Geoscience, 11(4):251-257.

JAMBECK J R, GEYER R, WILCOX C, et al, 2015.

Plastic waste inputs from land into the ocean

[J]. Science, 347(6223):768-771.

Plastic debris in the marine environment is widely documented, but the quantity of plastic entering the ocean from waste generated on land is unknown. By linking worldwide data on solid waste, population density, and economic status, we estimated the mass of land-based plastic waste entering the ocean. We calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025.

LAMB J B, WILLIS B L, FIORENZA E A, et al, 2018.

Plastic waste associated with disease on coral reefs

[J]. Science, 359(6374):460-462.

URL     PMID:29371469

LAVERS J L, BOND A L, 2017.

Exceptional and rapid accumulation of anthropogenic debris on one of the world’s most remote and pristine islands

[J]. Proceedings of the National Academy of Sciences of the United States of America, 114(23):6052-6055.

In just over half a century plastic products have revolutionized human society and have infiltrated terrestrial and marine environments in every corner of the globe. The hazard plastic debris poses to biodiversity is well established, but mitigation and planning are often hampered by a lack of quantitative data on accumulation patterns. Here we document the amount of debris and rate of accumulation on Henderson Island, a remote, uninhabited island in the South Pacific. The density of debris was the highest reported anywhere in the world, up to 671.6 items/m(2) (mean +/- SD: 239.4 +/- 347.3 items/m(2)) on the surface of the beaches. Approximately 68% of debris (up to 4,496.9 pieces/m(2)) on the beach was buried <10 cm in the sediment. An estimated 37.7 million debris items weighing a total of 17.6 tons are currently present on Henderson, with up to 26.8 new items/m accumulating daily. Rarely visited by humans, Henderson Island and other remote islands may be sinks for some of the world's increasing volume of waste.

LEBRETON L C M, VAN DER ZWET J, DAMSTEEG J W, et al, 2017.

River plastic emissions to the world’s oceans

[J]. Nature Communications, 8:15611.

URL     PMID:28589961

MASUMOTO Y, SASAKI H, KAGIMOTO T, et al, 2004.

A fifty-year eddy-resolving simulation of the world ocean — Preliminary outcomes of OFES (OGCM for the Earth Simulator)

[J]. Journal of the Earth Simulator, 1:35-56.

MAXIMENKO N, HAFNER J, NIILER P, 2012.

Pathways of marine debris derived from trajectories of Lagrangian drifters

[J]. Marine Pollution Bulletin, 65(1-3):51-62.

Global set of trajectories of satellite-tracked Lagrangian drifters is used to study the dynamics of marine debris. A probabilistic model is developed to eliminate the bias in spatial distribution of drifter data due to heterogeneous deployments. Model experiments, simulating long-term evolution of initially homogeneous drifter array, reveal five main sites of drifter aggregation, located in the subtropics and maintained by converging Ekman currents. The paper characterizes the geography and structure of the collection regions and discusses factors that determine their dynamics. A new scale R(c)=(4k/|D|)((1/2)) is introduced to characterize tracer distribution under competing effects of horizontal divergence D and diffusion k. Existence and locations of all five accumulation zones have been recently confirmed by direct measurements of microplastic at the sea surface.

SASAI Y, ISHIDA A, YAMANAKA Y, et al, 2004.

Chlorofluorocarbons in a global ocean eddy-resolving OGCM: pathway and formation of Antarctic bottom water

[J]. Geophysical Research Letters, 31(12):L12305.

SASAKI H, NONAKA M, MASUMOTO Y, et al, 2008.

An eddy-resolving hindcast simulation of the quasiglobal ocean from 1950 to 2003 on the Earth Simulator

[M]// HAMILTON K, OHFUCHI W. High Resolution Numerical Modelling of the Atmosphere and Ocean. New York, NY: Springer, 157-185.

SASAKI H, SASAI Y, KAWAHARA S, et al, 2004.

A series of eddy-resolving ocean simulations in the world ocean-OFES (OGCM for the Earth Simulator) project

[C]// Oceans ’04 MTS/IEEE Techno-Ocean ’04 (IEEE Cat. No.04CH37600). Kobe, Japan: IEEE, 3:1535-1541.

SAVOCA M S, WOHLFEIL M E, EBELER S E, et al, 2016.

Marine plastic debris emits a keystone infochemical for olfactory foraging seabirds

Plastic debris is ingested by hundreds of species of organisms, from zooplankton to baleen whales, but how such a diversity of consumers can mistake plastic for their natural prey is largely unknown. The sensory mechanisms underlying plastic detection and consumption have rarely been examined within the context of sensory signals driving marine food web dynamics. We demonstrate experimentally that marine-seasoned microplastics produce a dimethyl sulfide (DMS) signature that is also a keystone odorant for natural trophic interactions. We further demonstrate a positive relationship between DMS responsiveness and plastic ingestion frequency using procellariiform seabirds as a model taxonomic group. Together, these results suggest that plastic debris emits the scent of a marine infochemical, creating an olfactory trap for susceptible marine wildlife.

VAN SEBILLE E, ENGLAND M H, FROYLAND G, 2012.

Origin, dynamics and evolution of ocean garbage patches from observed surface drifters

[J]. Environmental Research Letters, 7(4):044040.

WALLER C L, GRIFFITHS H J, WALUDA C M, et al, 2017.

Microplastics in the Antarctic marine system: an emerging area of research

[J]. Science of the Total Environment, 598:220-227.

URL     PMID:28441600

YAMASHITA R, TANIMURA A, 2007.

Floating plastic in the Kuroshio Current area, western North Pacific Ocean

[J]. Marine Pollution Bulletin, 54(4):485-488.

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