Microplastics and large plastic debris in Hong Kong waters

Dr. FOK Lincoln, LAM Wing Ling, NG Ka Lok, LI Hin Kit, YEUNG Ling Chun, JIA Zhong Nan

霍年亨博士、林詠玲、吳嘉洛、李憲杰、楊令衠、賈柊楠

塑膠圍港｜ 2O18香港海域塑膠分佈

摘要 Abstract P.2

引言 Introduction P.3-4

研究方法 Methodology P.5-6

分析結果 Result P.7-10

結論及討論 Conclusion and Discussion P.11-12

綠色和平倡議 Greenpeace recommendations P.13-14

嗚謝 Acknowledgement P.14

英文版 English version P.15-24

附錄 Appendix P.25

參考文獻 References P.25-26

本報告記錄了綠色和平船艦「彩虹勇士號」於2018

年1月在香港水域採樣調查海洋垃圾的結果。此調

查利用採樣工具網Manta net在香港水域沿岸共20

個採樣點，在海面收集樣本，再抽取塑膠垃圾並分析

其大小、形態、類別、聚合物。結果顯示，全部採樣點

均收集到微塑膠（0.355至4.75毫米）及較大塑膠碎片

（>4.75毫米），濃度平均值（±標準誤差，SEM）分別

為每立方米2.936顆（n/m3）及0.202 顆（n/m3）。當

中微塑膠的聚合物主要屬聚苯乙烯（PS）及聚乙烯

（PE）；並以聚苯乙烯泡沫（俗稱「發泡膠」）及透

明薄膜等類型為主。有關結果與香港社會慣常使用

發泡膠容器及塑膠包裝的狀況吻合。研究結果顯示

香港吐露港及東部水域錄得的微塑膠濃度，明顯高

於香港西部水域，反映出大量漂浮在香港水域的塑

膠垃圾有部分是由本地產生的。

摘 要

研究團隊在彩虹勇士號上記錄和收集塑膠垃圾樣品。

目 錄 Table of contents

© Vincent Chan / Greenpeace

© Vincent Chan / Greenpeace

1 2

隨著需求日益增長，塑膠早已投入大規模生產，應用

範圍亦日益廣泛，例如護膚產品中的微膠珠（Masura

et al., 2015）及製衣業的合成纖維（Thompson et

al., 2004; Browne et al., 2007）。過去數十年，全球

塑膠物料產量急劇增長，至2017年已達到3.48億噸

（PlasticsEurope, 2018）。近期有研究指出，超過

95%的人為海洋垃圾是塑膠碎片（Galgani et al .,

2015）。據估計，每年有多達115萬至241萬噸的陸上

塑膠碎片，經由河流進入全球海洋（Jambeck et al.,

2015; Lebreton et al., 2017）。

香港是一個人口達740萬的大都會（香港特別行政區

政府統計處，2018）。種種證據指出，香港已成為微塑

膠污染熱點（Fok & Cheung, 2015）。 本地社會廣泛

使用即棄塑膠產品，包括食品包裝及發泡膠食物容器

（Fok & Cheung, 2015）。2017年，香港的都市固體

廢物達到392萬噸，當中20%為塑膠廢物（香港環境保

護署，2019）。雖然香港設有妥善的廢物管理系統，但

香港全年降雨量高（2018年雨量為2163毫米，香港天

文台，2019b）加上颱風等驟起的風暴，或會引致一些

未經妥善管理的塑膠垃圾流入海洋環境。

除本地污染源頭外，珠江亦是香港水域塑膠污染的來

源之一。珠江是中國其中一個最大型的流域，面積達

453,700平方公里（珠江水利委員會，2018）。在2016

年，中國的塑膠年產量達到8,300萬噸（中國國家統計

局，2018）。其中廣東省生產了670萬噸塑膠原料。然

而，Gu et al.（2017）指出，中國農村地區的廢物管理

發展落後。管理不善的塑膠廢物經由地表徑流進入河

流，最終落入南中國海（Cheung et al., 2018）。

1 . 引 言

微塑膠是直徑小於5毫米的塑膠微粒（Arthur et al.,

2009; Kershaw et al., 2015）。它們或由於工業及商業

應用而被直接製造出來（原始微塑膠），亦可能是大型

塑膠經由海浪沖刷、水解，微生物降解及光降解等在環

境中分裂（次生微塑膠；Wright et al., 2013）。現行污水

處理系統無法完全隔除污水中的微塑膠（Brown et al.,

2007），部分塑膠碎片，特別是體積細小的微塑膠，因

而流入海洋環境。由於微塑膠的大小及外觀與沉積物

和浮游生物相似，有多項研究發現，多種生物曾誤食微

塑膠（Blight & Burger, 1997; Gregory, 2009; Cole et

al., 2013）。生物誤食微塑膠不僅可導致內傷及阻塞腸

道，亦可導致生育率及逃避捕食者的能力下降（Laist,

1997; Derraik, 2002; Gregory, 2009）。此外，微塑膠

會吸附化學物質或有毒物質，並作為傳輸污染物的載體

（Andrady, 2011; Frias et al., 2010）。

為調查香港沿岸水域塑膠污染的嚴重程度，本研究旨

在研究吐露港、香港東部及西部水域中，水面上的塑

膠垃圾濃度及分佈。另亦會研究在香港水域發現的

塑膠之大小、形態、類別、聚合物。由於本研究在旱季

（2018年1月）進行，故所得數據並不代表香港水域中

微塑膠和較大塑膠碎片的全年平均濃度。

颱風「山竹」過後，大批塑膠垃圾隨着海水湧上岸。

香港塑膠垃圾隨處可見，影響生態以至人體健康。

© Greenpeace

© Marco Garcia / Greenpeace

3 4

E1

T1T2T3

E2E3

E4

E5

E6W1W2

W3W5W6W7W8

W9

W10

W11

W4

2.1 採樣

本研究在香港沿岸水域共選取了20個採樣點（圖1），

其中3個位於吐露港（採樣點T1至T3）、6個位於東部

水域（採樣點E1至E6），其餘屬西部水域（採樣點

W1至W11）。採樣工作於2018年1月進行（1月5日至

8日及12日至15日）。按照Cheung et al.（2018）採

用的方法，利用採樣工具網Manta net收集漂浮海

面的碎片樣本，其矩形開口為0.87x 0.16平方米，並

附以一個網眼為333微米的網，及一個可拆式囊網

（cod-end）。此外，網口中央安裝了一個流量計，

以測量每次拖行時所過濾的水量。每個採樣點均會

2 . 研 究 方 法

使用兩個拖網同步採樣，並以2節的船速在水面拖

行20分鐘，然後將網拉回船上徹底沖洗，而各囊網

的內容物隨後保存在密封塑膠袋中，再送交實驗室

分析。

2.2 樣本處理

在實驗室內，研究人員使用經過濾的去離子水沖

洗樣本，並放入燒杯中。去除有機物質後進行大

小分級。塑膠碎片分為5個大小級別：（1）0.355-

0.499毫米；（2）0.500-0.709毫米；（3）0.710-

2.749毫米；（4）2.800-4.749毫米及（5）≥4.750

圖1 香港水域的採樣點（T1至T3位於吐露港；E1至E6位於香港東部 水域；W1至W11位於香港西部水域。各採樣點的名稱及座標，請參閱英文版附錄）

毫米（Cheung et al., 2018）（圖2）。本研究根據

Hanvey et al.（2017），將前4個級別的塑膠定義為

「微塑膠」，第5級別則為「較大塑膠碎片」。

研究人員使用放大率最高達45倍的立體顯微鏡進行

塑膠微粒的分類及計量。塑膠微粒按形態被劃分為五

類，包括（1）聚苯乙烯泡沫（polystyrenefoam,PF）、

（2）纖維（fibre,FB）、（3）薄膜（film,FL）、（4）碎片

（fragment,FM）及（5）顆粒（pellet,PL）。此外，塑

膠碎片亦會按顏色分為四類：（1）白色、（2）透明、

（3）有色及（4）黑色。塑膠碎片經分類後，會被烘乾

再測量重量，精確至0.0001克。

為確定經分選的塑膠碎片之聚合物成分，隨機選

擇碎片並使用衰 減全反射傅立葉紅外線（ATR-

FTIR）光譜儀分析。

2.3 分析結果

由於各採樣點均使用兩個拖網同步採樣，故會計算

兩者的塑膠碎片平均濃度，並以平均數值作統計分析

之用。數量及重量的數值均以每立方米（m3）表示，

即分別為「每立方米海水的塑膠物數量」（n/m3）及

「每立方米海水的塑膠物淨重量」（mg/m3）。有關

統計檢定方法詳情，請參閱英文版。

2.4 實驗質量控制 （請參閱英文版）

使用FTIR-傅立葉紅外線光譜儀來分析塑膠碎片的聚合物。

© Patrick Cho / Greenpeace

5 6

硬膠

碎片

3,784件

| 20.9

%

塑膠

薄膜

3,158件

| 17.4

%

3 . 分 析 結 果

發泡

膠

7,429件

| 41.0

%

塑膠

纖維

3,716

件 | 2

0.5%

（原

材料

）膠粒

36件

| 0.2

%

18.1 %

60.9 %

0.7 %

2.2 %

6.7 %

分別為不同聚合物 5 大類塑膠類型

在吐露港、東部水域及西部水域採集的微塑膠濃度

不同地區的微塑膠濃度

2.344 件/立方米 7.637 件/立方米 0.534 件/立方米

吐露港

香港沿岸水域 香港沿岸水域（2015） 南中國海 東海沿岸水域 葡萄牙沿岸水域

東部 西部

微塑膠（0.355 – 4.749 毫米）

2.936 ± 1.211 0.256 ± 0.092 0.045 ± 0.093 0.167 ± 0.138 介乎 0.002 - 0.036

3.1 整體塑膠碎片濃度

所有採樣點合共收集到18,123件塑膠碎片，其中94.0%為微塑膠（0.355-4.749毫米）。較大塑膠碎片僅

佔6.0%。微塑膠中，濃度介乎0.191至20.8 n/m3，濃度總平均值（±SEM）為2.936 ± 1.211n/m3；淨重平均

濃度則為0.263 ± 0.126 mg/m3。較大塑膠碎片中，整體數量與淨重的總平均濃度（±SEM），分別為0.202

± 0.082 n/m3 及 2.496 ± 0.925 mg/m3。

微塑膠（0.355 - 4.749 毫米）- 東部水域錄得的微塑膠平均濃度最高（7.637n/m3），其次為吐露港

（2.344 n/m3）及西部水域（0.534 n/m3）。此外，濃度中位數以東部水域最高（5.355 n/m3），西部水

域最低（0.414 n/m3）。

較大塑膠碎片（≥4.750毫米）- 東部水域錄得的較大塑膠碎片平均濃度最高（0.549n/m3），其次為

吐露港（0.110 n/m3）及西部水域（0.038 n/m3）。

a 採用Kruskal-Wallis H 檢定法，以測試吐露港及香港東西水域錄得的濃度中位數是否相等。微塑膠濃度比較錄得有顯著差異（p < 0.05）（見粗體數字）。

a 採用Mann-Whitney U檢定法，以測試濃度中位數是否相等。顯著差異（見粗體數字）僅見於香港東西水域之間的配對比較（p = 0.012 < 0.05）。

3.2 塑膠碎片在不同水域的比較

吐露港

吐露港 東西水域 東部水域 西部水域

3

3 17 6 11

吐露港

3

東部

6

東部

6

西部

11

西部

11

數量（n/m3）

數量（n/m3）

平均值最低值最高值

平均值最低值最高值

p值a

p值a

2.3440.5125.089

2.3440.5125.089

3.0410.191

20.843

7.6370.639

20.843

0.5340.1910.895

0.1100.0090.262

7.6370.639

20.843

0.016

0.315

0.5490.0211.165

0.103

0.012

0.5340.1910.895

0.0380.0030.098

N

N

表1a 在吐露港、東部水域及西部水域採集的微塑膠（0.355-4.749毫米） 及較大塑膠碎片（≥4.750 毫米）之數量（n/m3）數據摘要

表1b 吐露港與東西水域以及香港東西水域之間的微塑膠濃度（n/m3）配對比較

微塑膠（0.355 - 4.749 毫米）

微塑膠（0.355 - 4.749 毫米）

較大塑膠碎片（≥4.750 毫米）

PE

PS

其他塑膠

未能確定

非塑膠

11.4 %PP, PP/EPR

濃度 （件/立方米 ±標準誤差）

7 8

3.3 可辨認的塑膠碎片之特徵

大小介乎0.355-4.749毫米的塑膠顆粒（即微塑膠）佔所有塑膠碎片的94.0%。按塑膠形態

類別劃分，則微塑膠多屬聚苯乙烯泡沫（即發泡膠）（42.3%），其次為碎片（21.5%）及

纖維（18.7%）。較大塑膠碎片則主要是纖維（48.8%），其次為聚苯乙烯泡沫（19.8%）

及薄膜（19.6%）。顏色方面，白色的塑膠碎片佔最多（55.3%），黑色則最少（5.1%）。其

中，微塑膠以白色為主（56.9%），塑膠碎片則多屬有色的（40.9%）。

7951個經目測分類的物品中，選取905個（11.4%）以ATR-FTIR進一步分析其聚合物成分。

結果合共鑑別出16種聚合物，當中以聚苯乙烯（PS）佔最多（60.9%），其次為聚乙烯（PE,

LDPE, MDPE: 18.1%）及聚丙烯／乙丙橡膠（PP/EPR: 7.0%）。其他鑑別出的聚合物尚有聚

丙烯（PP: 4.4%）、三元乙丙橡膠（EPDM: 0.6%）、乙烯—醋酸乙烯酯（EVA:0.1%）（表4）。

數量

數量 數量 數量

18,123

18,123 17,034 1,089

數量

2,385

數量

數量

13,786

數量

%

1,952

%

% % %

100

100 100 100

%

100

%

100

%

100

大小範圍 （毫米）

聚合物

塑膠類型

總數

總數

5,3254,8475,2241,6381,089

7,4293,7163,1583,784

36

7,2133,1852,9443,659

33

2165312141253

0.355 - 0.4990.500 - 0.7090.710 - 2.7992.800 - 4.749

≥ 4.750

聚乙烯 (PE), 低密度聚乙烯 (LDPE), 中密度聚乙烯 (MDPE) 聚丙烯 (PP), 聚丙烯／乙丙橡膠 (PP/EPR) 聚苯乙烯 (PS) 其他塑膠 未能確定非塑膠

經檢測分析塑膠

聚苯乙烯泡沫（PF）纖維（FB）薄膜（FL）碎片（FM）顆粒（PL）

29.426.828.89.06.0

41.020.517.420.90.2

42.318.717.321.50.2

19.848.819.611.50.3

816594702167106

34.224.929.47.04.5

3,7353,5024,3421,357850

1641035516

2061

905824

27.125.431.59.86.2

774751180114133

18.111.460.90.72.26.7

10091.1

39.738.59.25.86.8

表2 香港水域收集到的塑膠碎片的大小分布

表4 ATR-FTIR鑑別得出的聚合物

表3 按塑膠形態類別劃分的微塑膠及較大塑膠碎片的數量

整體

整體 微塑膠（0.355-4.749 毫米） 較大塑膠碎片（≥4.750毫米）

吐露港 東部水域

整體（樣本分類前）

西部水域

1

2

3

4

A B C D E

圖 3 立體顯微鏡下鑑別出的微塑膠：(a)聚苯乙烯泡沫、(b)纖維、(c)薄膜、(d)碎片及(e)顆粒。比例尺代表1毫米。

微塑膠是指直徑或長度少於5毫米的塑膠碎片，它們有不同的形態類別，例如碎片、纖維或薄膜等。

3 . 分 析 結 果

© Vincent Chan / Greenpeace © Fred Dott / Greenpeace

9 10

4 . 討 論 及 結 論

其他研究提及不同地區的微塑膠濃度，與之比較，本研究錄得的微塑膠濃度水平亦高於其

他受塑膠污染地區，包括南中國海（Cai et al., 2018）及東海沿岸水域（Zhao et al., 2014；

表 5）。

本研究顯示香港水域已受到塑膠污染。我們的研究發現，2018

年旱季的平均微塑膠濃度為2.936 ± 1.211 n/m3，數字大致高

於2015年旱季進行的同類研究（Cheung et al., 2018），當時錄

得的平均微塑膠濃度為0.256 ± 0.092 n/m3。

是次研究看到的微塑膠分佈，或是由於採樣工作首星期間曾降雨所致。降雨量對海洋環境

中的塑膠碎片分佈起著重要作用（Ivar do Sul et al., 2013），因為風雨可以加劇陸地

塑膠碎片轉移到海洋環境的情況。已有多項研究表明，微塑膠濃度在雨季時或暴雨後較

高。Cheung et al.（2018）的一項研究發現，香港海面的平均微塑膠濃度在雨季時（6.124

± 2.121 n/m3）高於旱季時（0.256 ± 0.092 n/m3）逾23倍。Moore et al（2002）亦曾

發表研究報告指，美國加州南部沿岸水域錄得的塑膠碎片數量，在暴風雨後增加了6倍。

上述研究證明，降雨量是影響微塑膠濃度的關鍵因素。本研究在2018年1月7日至8日採樣

期間（即於東部水域取樣期間），分別錄得16.2毫米及11.6毫米的雨量。根據香港天文台

（2018a）資料，2018年1月的月降雨量為62.2毫米，而在東部水域的取樣點一帶，1月7日

錄得的降雨量介乎20至30毫米。西部水域的採樣工作在2018年1月12日至15日進行時，則

未有錄得降雨量。這或許解釋了東部水域的平均微塑膠濃度，為何會明顯高於西部水域及

高於Cheung et al.（2018）在2015年旱季錄得的水平。儘管如此，由於本研究於旱季進

行，在一個月間錄得的結果並不能反映全年平均值，故或需要作進一步的調查，以顧及季節

性的影響，才能更準確了解香港水域中微塑膠在不同時節及天氣之分佈。

東部水域較西部水域錄得較高的微塑膠濃度。在全部20個採樣點中，錄得微塑膠濃度最高

的3個採樣點為E1、E4及E5，西部水域錄得的微塑膠濃度則介乎0.191至0.895 n/m3。這顯

示香港水域的塑膠碎片主要來自香港市內，例如市民亂拋垃圾、污水渠排放、海上運輸和

工業活動（Tsang et al., 2017）。

在3個調查區域中，吐露港錄得的微塑膠平均濃度為第二高，即2.344 ± 1.398 n/m3。吐露

港為一個半封閉的淺水水體，目前已因運輸、廢物處理、拖網捕撈、養魚等人類活動而面臨

各種環境威脅（Owen & Sabdhu, 2000）。曾有研究指出，在封閉及半封閉區域會錄得較

高的微塑膠濃度（Barnes et al., 2009）。由於吐露港在旱季時需要長達38天時間沖刷淨

化，港口被陸地圍繞的情況經常導致水體天然分層現象（香港環境保護署，2016）。吐露港

沖刷淨化需時，代表降雨帶來的碎片更容易囤積（香港環境保護署，2009），引致港內塑膠

碎片濃度相對較高。

在本研究中，聚苯乙烯泡沫（發泡膠）（PF）為最主要的微塑膠類別（42.3%），並佔白色

微塑膠的73.9%。香港兩項研究亦曾有類似發現，分別指出聚苯乙烯泡沫（發泡膠）為2014

年雨季在沙灘（40.7%）及2015年旱季在海面（92%）發現到的最主要微塑膠類別（Fok &

Cheung, 2015; Cheung et al., 2018）。聚苯乙烯泡沫（發泡膠）廣泛應用於食品包裝及

易碎物品保護包裝，因其容器價格廉宜、輕巧、防水及耐熱（Cheung et al., 2018）。此外，

透明微塑膠（21.2%）是在香港水域發現的微塑膠中第二最多的顏色類別，其中分別有

55.8%及28.5%的透明微塑膠為薄膜及碎片。這與透明塑膠製品的常見用途相關，例如

食品包裝（Zhao et al., 2014）。

表5 本研究與其他研究提及不同地區的微塑膠濃度之比較。本研究的資料以粗體表示。

香港沿岸水域

香港沿岸水域（2015）

南中國海

東海沿岸水域

葡萄牙沿岸水域

Manta trawl

Manta trawl

Bongo trawl

Neuston net trawl

Neuston net trawl

2.936 ± 1.211

0.256 ± 0.092

0.045 ± 0.093

0.167 ± 0.138

介乎0.002 - 0.036

本研究

Cheung et al., 2018

Cai et al., 2018

Zhao et al., 2014

Frias et al., 2014

333

333

333

333

280

旱季

旱季

旱季

雨季

未有提供

研究地點 研究方法 參考濃度

（n/m3 ± SEM） 網眼尺寸

(微米) 季節

11 12

5 . 綠 色 和 平 倡 議

香港水域已遍佈主要來自香港的市內塑膠垃圾。綠色和平在香港沿岸水域共20個地點取

樣，全部均採集到微塑膠和較大塑膠碎片，大部份屬聚苯乙烯(PS)及聚乙烯(PE)兩種主要

用在即棄食品包裝的塑膠複合物，研究結果反映生產商和零售商過度包裝食品的問題，正

正就是解決「塑膠圍港」的下一個主要戰場，而企業和政府亦必須立即行動作出改革。

綠色和平建議，政府應趕上國際步伐，盡快訂立減塑目標、時間表及具體的行動方案：

綠色和平建議企業以減少使用塑膠為原則，改革產品包裝及銷售方式：

特此鳴謝綠色和平船艦「彩虹勇士號」支持採樣工作，並感謝香港教育大學環境科學系的呂

靜宜小姐、吳泳楠小姐、徐家美小姐、周藹銓小姐協助採樣及分析。

首先立法管制使用難以回收的即棄塑膠，如即棄塑膠餐具、即棄發泡膠

餐盒，長遠應全面禁止使用。

針對市面的過度包裝塑膠，政府應盡快規管，如落實生產者責任制，要求

生產商減少使用及回收其產品的包裝物料等。

訂立減塑目標及時間表，並承諾以減量而非回收作為解決方法，阻止塑膠

圍港發生。

定期檢驗香港海域、河流及飲用水中微塑膠含量，監控塑膠污染情況，並

公開檢測數據。

減少不必要的產品包裝及提供無包裝銷售形式：不少預先包裝的食品使

用多層塑膠，常見於生果、蔬菜或禮盒裝的糖果零食。生產商及零售商應

立刻從產品設計及銷售方面著手改革，減少甚至完全淘汰即棄塑膠包裝，

並轉向以可重用或無包裝的形式販售。

成立跨界別合作平台，與民間團體、商界及其他持份者定期交換意見，在

各自範疇多推廣減用塑膠、善用資源，並且攜手加強公民教育，鼓勵市民

在日常生活盡量少用即棄塑膠。 針對即棄餐具，連鎖快餐企業須針對外賣的塑膠問題對症下藥，邁向走

塑。例如提供外賣走塑優惠或不主動提供非必要的塑膠餐具。

政府

企業

過度包裝也是污染海洋元凶之一。 不少超市也會使用大量即棄塑膠來包裝新鮮蔬果。

參考外國已經實行的例子，不少食品企業已經訂立3-5年的減塑目標，

而且重新設計產品包裝，儘量以其他物料取代即棄塑膠。在零售方面，

更可設立無包裝的銷售區域，讓顧客按份量自備器皿購買，或是以可退

回的器皿售賣貨品。

鳴謝

© Steve Morgan / Greenpeace© Greenpeace

13 14

This report documents the results of a marine debris survey in Hong Kong waters carried out onboard the

Greenpeace Rainbow Warrior vessel in January 2018. Water surface samples were collected by manta nets at

20 coastal locations in Hong Kong. Both microplastics (0.355 – 4.75mm) and large plastic debris (>4.75 mm) were

detected from all sites with mean (± SEM) abundances of 2.936 ± 1.211 n/m3 and 0.202 ± 0.082 n/m3, respectively.

Microplastics comprised 94.0% of the debris by number. Microplastic abundance was significantly higher in the

Eastern waters than in the Tolo Harbour and the Western waters. Microplastics were predominately composed of

polystyrene (PS) and polyethylene (PE). White polystyrene foam and transparent film were the major microplastic

types found in Hong Kong waters. This result correlates with the prevalent use of foam containers and plastic

packaging in Hong Kong.

Plastics are durable, corrosion and chemical resistant, cheap and

lightweight when compared to traditional materials, such as wood and

metals (Laist, 1987). With a rising demand, plastics have been mass

produced and increasingly used in a growing variety of applications, for

example, microbeads in skin care products (Masura et al., 2015) and

synthetic fabrics used for garment manufacturing (Thompson et al.,

2004; Browne et al., 2007). Over the past few decades, the annual world

production of plastic materials has increased dramatically and has reached

348 million tonnes in 2017 (PlasticsEurope, 2018). Due to a culture of

disposability and inefficient waste management, disposal of plastic waste

becomes ordinary. Recent studies have shown that plastic debris made

up over 95% of anthropogenic litter in the oceans (Galgani et al., 2015). It

was estimated that between 1.15 and 2.41 million tonnes of land-based

plastic debris enters the world’s oceans every year from rivers (Lebreton et

al., 2017). The end result is the ubiquitous presence of plastic debris in the

world's oceans, amounting to over 5.25 trillion pieces floating on the sea

surface (Eriksen et al., 2014). Owing to the rampant proliferation of plastic

debris in the marine environment, public and scientific awareness on the

issue has been increasing.

Microplastics are tiny plastic particles of less than 5 mm in diameter

(Arthur et al., 2009; Kershaw, 2015). They are either directly manufactured

for industrial and commercial applications (primary microplastics) or

fragmented from larger debris through mechanical (including wave action

and hydrolysis), microbial and photo-degradation in the environment

(secondary microplastics; Wright et al., 2013). As above-mentioned, a

portion of plastic debris entered the marine environment due to leakages

in waste management systems. Microplastics can leak easily due to

their size. The current water treatment systems are unable to remove

microplastics in sewage completely (Brown et al., 2007). Due to their

Abstract

1. Introduction

similarities in size and appearance to sediment and plankton species,

microplastic ingestion is common (Setälä et al., 2014; Farrel & Nelson,

2013; Lusher et al., 2013; Wright et al., 2013). Previous studies have

reported the ingestion of microplastics by a wide range of organisms

(Blight & Burger, 1997; Gregory, 2009; Cole et al., 2013). The uptake

of microplastics may lead not only to internal injuries and intestinal

blockage, but also reduced fertility and predator avoidance (Laist, 1987;

Derraik, 2002; Gregory, 2009). Furthermore, microplastics are prone to

adsorb chemicals or toxic substances and therefore work as a vector for

transporting pollutants in the environment and into the biota (Andrady,

2011; Frias et al., 2010).

Hong Kong is a metropolitan city with a population of 7.4 million (Census

and Statistics Department of HKSAR, 2018). Evidence suggests the city

is a hotspot of microplastic pollution (Fok & Cheung, 2015). Single-use

plastic products, including food packaging and foam food containers, are

widely used locally (Fok & Cheung, 2015). In 2017, the annual amount of

municipal solid waste generated was 3.92 million tonnes, of which 20% was

plastics (HKEPD, 2019). Although Hong Kong has a state-of-the-art waste

management system, the high annual rainfall (2018 annual total rainfall:

2163 mm; Hong Kong Observatory, 2019b) coupled with occasional flash

flood-inducing storms such as typhoons, may deliver mismanaged plastic

waste into the marine environment. Apart from local sources, the Pearl

River is known to be one of the sources of plastic pollution in Hong Kong

waters. The Pearl River is one of the largest catchments in China with an

area of 453,700 km2 (Pearl River Water Resources Commission, 2018).

In 2016, annual production of plastic materials in China amounted to

83 million tonnes (National Bureau of Statistics of China, 2018). Among

which, 6.7 million tonnes of plastic materials were produced in Guangdong

Province. Nonetheless, Gu et al. (2017) indicated that waste management

in rural areas in China is under-developed. Carried by surface runoff,

mismanaged plastic waste enters rivers and eventually into the South

China Sea (Cheung et al., 2018).

To investigate the severity of plastic pollution in the coastal waters of Hong

Kong, this study aimed to examine the spatial variations in the abundance

of floating plastic debris in the Tolo Harbor, Eastern and Western waters

of Hong Kong. Moreover, the abundance, sizes, colors and compositions of

plastic debris found in Hong Kong waters were analysed.

15 16

Reduce the speed of Rainbow Warrior to 2 knots

Record sampling time, location, seawater salinity,

and weather conditions

Deploy two Manta nets on the sides of Rainbow Warrior and trawl for 20 minutes to

sample microplastic from the sea surface

Examine and categorise samples into 5 types of micro-

plastics in the laboratory

Use FTIR spectrometer to analyse the composition

of microplastics

1 2 3 4 5

2.1 Sampling

In this study, a total of 20 sites were selected in the

coastal waters of Hong Kong. Three of them are

located in the Tolo Harbor (site T1 to T3), six in the

Eastern waters (site E1 to E6), while the rest in the

Western waters (site W1 to W11). Sampling was

conducted on January 5th to 15th, 2018 with a break

between January 9th and 11th. Following the method

adopted by Cheung et al. (2018), floatable marine

debris samples were collected by manta nets (Ocean

Instruments Inc., San Diego, USA) which have a

rectangular opening of 0.87 x 0.16 m2. The net frame

was attached to a net and a detachable cod-end

with a mesh size of 333μm. A flowmeter (General

Oceanics Inc., Model: 2030R) was also mounted in the

center of the net mouth for measuring the volume

of water filtered in each tow. At each sampling site,

two trawls were carried out in parallel. To avoid the

collection of non-representative samples affected

by ship wakes, the nets were deployed out of and

faced away from the ship’s wake zone. The nets were

towed at the air-sea interface for 20 minutes at a

speed of 2 knots. The nets were then lifted onboard

and thoroughly rinsed with seawater from the

outside, with a direction starting from the net mouth

downward to the cod-end. Contents retained in

each cod-end were transferred to a labelled, sealable

plastic bag with deionized water, mixed with 30%

formalin and stored for laboratory analysis.

2.2 Digestion and size fractionation of samples

In the laboratory, samples were rinsed with filtered

deionized water and place into beakers. To remove

2.3 Density separation and visual sorting

All floating particles were separated from the

saturated saline solution via floatation. Samples

within the first two classes (i.e. 0.355–0.499 and

0.500–0.709 mm) were subsampled using a

Folsom plankton sample splitter (Aquatic Research

Instruments, USA) and vacuum filtered through

a mixed cellulose ester filter (Advantec, Japan,

diameter: 47 mm, pore size: 0.45 μm). The filters

were sealed in petri dishes with lids and oven dried at

60°C for 24 hours. Classification and numeration of

particles were carried out under a stereo-microscope

at up to 45X magnification (Olympus, Tokyo, Japan,

Model: SZ61). Plastic particles were classified and

counted into five categories, including (1) polystyrene

foam (PF), (2) fibre (FB), (3) film (FL), (4) fragment (FM)

and (5) pellet (PL), based on the visual identification

criteria suggested by Hidalgo–Ruz et al. (2012) and

Cheung et al. (2016). Aside from this, plastic debris

was characterized by color and divided into four

groups: (1) white, (2) transparent, (3) colored and (4)

black. Moreover, samples in the remaining classes

(i.e. 0.710–2.749, 2.800–4.749, and ≥4.750 mm) were

rinsed from the sieves and re-suspended in tap water

for visual identification. Items were visually sorted

into the above mentioned categories and counted

by naked eyes. The sorted plastic items were then

oven-dried at 60°C for 24 hours and weighted to the

nearest 0.0001g.

2.4 Verification of plastic items using ATR-FTIR

To determine the polymer composition of sorted

plastic debris, debris was randomly selected and

analyzed using an attenuated total reflection Fourier

2.5 Statistical analysis

As samples at each sampling site were collected by

parallel trawling, the average concentration of two

duplicates was calculated and used for statistical

analysis. Values were expressed in cubic meter (m3),

by number and weight using the concentration units

of “the number of plastic items per cubic meter of

sea water” (n/m3) and “the dry weight of plastic items

per cubic meter of sea water” (mg/m3), respectively.

Statistical tests were performed using IBM SPSS

software (version 25). As the data did not approach a

normal distribution (Shapiro-Wilk test: p-value < 0.05),

non-parametric tests were performed. Differences

among multiple groups were analyzed by the Kruskal–

Wallis H Test (Kruskal & Wallis, 1952). If the test showed

a statistically significant difference (p-value < 0.05),

paired–comparisons were then conducted with the

Mann-Whitney U Test (Mann & Whitney, 1947).

2.6 Quality control of experiments

To prevent aerial microplastic contamination during

sample processing, the following measures were

adopted. A cotton lab coat and nitrile gloves were

worn at all times. All work surfaces and equipment,

including laboratory glassware and sieves, were

previously rinsed with filtered deionized water

before use and thoroughly cleaned after each use.

Equipment and samples were immediately covered

with aluminum foil when they were not in use. In

addition, H2O

2 was filtered through a hardened

ashless filter paper (Chmlab Group, Spain, Model:

F2142-090, diameter: 90 mm, pore size: 20 μm) prior

to use to remove particulates. Filter papers soaked

with deionized water were placed in uncovered petri

dishes and put in the work area to detect airborne

contamination. The filter papers were then observed

under a stereomicroscope. No plastic particles were

found on any of the filters.

2. Methodology

Fig. 1. Sampling sites in Hong Kong waters. Sites T1 – T3 are located in the Tolo Harbor; sites E1–E6 are located in the eastern coastal waters of Hong Kong; sites W1–W11 are located in the western coastal waters of Hong Kong. See Appendix for the geographical coordinates of sampling sites.

and ‘large plastic debris’, respectively, according to the

terminology of microplastic quantification proposed by

Hanvey et al. (2017).

organic materials, the samples were placed on a

hotplate stirrer and treated with 30% hydrogen

peroxide (H2O

2) solution at 60 to 65°C for 24 to 72

hours. Digestion is considered as completed when the

solution turns clear or yellow, and there is no visible

particulate organic matter (Davidson & Dudas, 2016).

Size fractionation was carried out after the completion

of digestion. Each of the samples was poured through

a stack of stainless steel wire mesh sieves (aperture

size: 0.355, 0.5, 0.71, 2.8 and 4.75 mm), enabling plastic

debris to be fractionated into five size classes: (1) 0.355

– 0.499 mm; (2) 0.500 – 0.709 mm; (3) 0.710 – 2.749

mm; (4) 2.800 – 4.749 mm and (5) ≥4.750 mm (Cheung

et al., 2018). In this study, plastic items in the first four

classes and the last class are regarded as ‘microplastic’

E1

T1T2T3

E2E3

E4

E5

E6W1W2

W3W5W6W7W8

W9

W10

W11

W4

Transformed Infrared (ATR–FTIR) Spectrometer

(PerkinElmer Frontier, Schwerzenbach, Switzerland).

All analyses were performed with 8 co-added scans

in transmission mode in the spectra range from 4000

to 550 cm-1. Items with a search score ≥0.7 were

accepted as a correct identification; items with a score

<0.7 but ≥0.6 were classified as undefined; items with a

score <0.6 were rejected and classified as non-plastic,

following the method adopted by Yang et al. (2015).

17 18

Polymer composition Plastic type

Microplastic densities in different regions

HK compared to other region

2.344 n/m3 7.637 n/m3 0.534 n/m3

Tolo Harbour Eastern Water Western Water

Density （n/m3 ± SEM）

2.936 ± 1.211 0.256 ± 0.092 0.045 ± 0.093 0.167 ± 0.138 0.002 - 0.036

3. Results

Hong Kong coastal waters (2015)

Coastal waters of East China Sea

Portuguese coastal watersSouth China Sea

a The weight data of microplastics only includes those in the range of 0.710 – 4.749 mm.

Table 1. Summary statistics of the densities of microplastics (0.355–4.749 mm) and large plastic debris (≥4.750 mm) by number (n/m3) and weight (mg/m3).

Microplastics (0.355 – 4.749 mm)

Number (n/m3)

Weighta

(mg/m3)

Large plastic debris (≥4.750 mm)

Overall 20 Overall 20

MeanSEM

MedianIQR

MinimumMaximum

MeanSEM

MedianIQR

MinimumMaximum

2.9361.2110.7610.8970.191

20.844

0.2630.1260.0410.2060.0052.356

0.2020.0820.0490.1160.0031.165

2.4960.9250.5654.4100.001

16.884

N

3.1 Overall plastic debris concentrationsA total of 18,123 plastic debris were collected from all sampling sites, of which 94.0% were

microplastics (0.355 – 4.749 mm). Large plastic debris only accounted for 6.0%. In terms of microplastics,

the concentrations by number ranged from 0.191 to 20.8 n/m3, with an overall mean (±SEM, standard error of

the mean) concentration of 2.936 ± 1.211 n/m3, while the mean concentration by dry weight was 0.263 ± 0.126

mg/m3. In terms of large plastic debris, the overall mean (±SEM) density by number and dry weight were 0.202 ±

0.082 n/m3 and 2.496 ± 0.925 mg/m3, respectively (Table 1).

3.2.1. Microplastics (0.355 – 4.749 mm) The highest mean density of microplastics by number was found in the

Eastern waters (7.637 n/m3), followed by the Tolo Harbour (2.344 n/m3) and the Western waters (0.534 n/m3; Table 2a).

The median concentration was the highest in the Eastern waters (5.355 n/m3), while the lowest concentration was found in the

Western waters (0.414 n/m3). The distribution of median concentration were significantly different among three investigated

areas (p = 0.016). Specifically, a significant difference (p = 0.012) was observed in the distribution of median concentration for the

Western and Eastern waters of Hong Kong (Table 2b). However, there was no statistically significant difference (p = 0.315 > 0.05)

between the Tolo Harbour (1.430 n/m3) and the combined dataset of the Eastern and Western waters (0.743 n/m3) with respect

to their median concentrations (Table 2b).

The comparisons of the mean and median concentrations by weight were similar to those by number. In general, the mean and

median concentrations in the Eastern waters were higher than those in the Tolo Harbour and the Western waters. However, the

comparison between three investigated areas did not show a significant difference (p = 0.239; Table 2a).

3.2.2. Large plastic debris (≥4.750 mm) The highest mean concentration of large plastic debris by number was found

in the Eastern waters (0.549 n/m3), followed by the Tolo Harbour (0.110 n/m3) and the Western waters (0.038 n/m3; Table 2a).

Similarly, the mean concentration by weight was the highest in the Eastern waters (4.984 mg/m3), followed by the Tolo Harbour

(2.111 mg/m3) and the Western waters (1.245 mg/m3; Table 2a). Their median densities also followed the same pattern. Despite

the fact that there were noticeable differences in the median densities by number and by weight, they were not significant.

3.2 Spatial comparison of plastic debris concentrations

18.1 %

60.9 %

0.7 %

2.2 %

6.7 %

PE

PS

other plastics

Undefined items

Non-plastic items

11.4 %PP, PP/EPR

Fragm

ent

3,784 p

iece

s | 20

.9%

Film

3,158 p

iece

s | 17

.4%

Polysty

rene

foam

7,429 p

iece

s | 41.0

%

Fibre

3,716

pie

ces |

20.5%

Pelle

t

36 pie

ces |

0.2%

Hong Kong coastal waters

19 20

Table 2a. Summary statistics of microplastic (0.355 – 4.749 mm) and large plastic debris (≥4.750 mm) densities in the Tolo Harbour, Eastern waters and Western waters of Hong Kong by number (n/m3) and weight (mg/m3).

Table 2b. Paired-comparisons of microplastic concentrations by number (n/m3) between the Tolo Harbour and the combined dataset (Eastern and Western waters), as well as the Eastern and Western waters of Hong Kong.

a The weight data of microplastics only includes those in the range of 0.710–4.749 mm.b Kruskal-Wallis H Test is used to test whether the median densities of the Tolo Harbor, Eastern waters and Western waters of Hong Kong are equal. A

signif icant difference (p < 0.05) (highlighted in bold) was found in the comparison of microplastic concentration by number.

a Mann-Whitney U Test is used to test whether the median densities are equal. A signif icant difference (highlighted in bold) only exists in the paired-

comparison of the Eastern and Western waters of Hong Kong (p = 0.012 < 0.05).

a Items with a search score ≥0.7. b Items with a search score <0.7 but ≥0.6. c Items with a search score <0.6 and items made of non-synthetic materials.

Fig. 3. Stereomicroscope images of identified microplastics: (a) polystyrene foam, (b) fibre, (c) film, (d) fragment and (e) pellet. Scale bars represent 1 mm.

Tolo

3

Tolo

3

East

6

East

6

West

11

West

11

Number (n/m3)

Weighta (mg/m3)

MeanSEM

MedianIQR

MinimumMaximum

pb

MeanSEM

MedianIQR

MinimumMaximum

pb

2.3441.3981.430

-0.5125.089

0.1770.1460.039

-0.0230.469

0.1100.7720.059

-0.0090.262

2.1111.3431.669

-0.0384.626

7.6373.4065.355

14.1600.639

20.8430.016

0.6770.3790.2831.4080.0102.3560.239

0.5490.2190.4871.0660.0211.1650.103

4.9842.6802.3199.8000.022

16.8840.365

0.5340.0750.4140.4790.1910.895

0.0610.0230.0290.0930.0050.229

0.0380.0090.0270.0520.0030.098

1.2450.6320.2641.1940.0016.128

N

Microplastics (0.355 – 4.749 mm) Large plastic debris (≥4.750 mm)

Tolo Combined dataset East West

3 17 6 11

Number (n/m3)

N

Microplastics (0.355 – 4.749 mm)

MeanSEM

MedianIQR

MinimumMaximum

pa

2.3441.3981.430

-0.5125.089

0.315 0.012

7.6373.4065.355

14.1600.639

20.843

3.0411.4150.7430.5300.191

20.843

0.5340.0750.4140.4790.1910.895

3.3 Characterization of identified plastic debrisPlastic particles (i.e. microplastics) in the size range 0.355 – 4.749 mm accounted for 94.0% of the total plastic debris. The

majority of microplastics identified in the Tolo Harbour and the Western waters was smaller than 0.71 mm, representing 59.1%

and 78.2% of the samples respectively. However, microplastics in size range 0.5 – 2.799 mm were the most abundant in the

Eastern waters (56.9%; Table 3). Regarding the plastic type, polystyrene foam (42.3%) was the predominant type of

microplastic, followed by fragment (21.5%) and fibre (18.7%). Fibre (48.8%) was the most abundant type of large plastic

debris, followed by polystyrene foam (19.8%) and film (19.6%). Among the microplastics and large plastic debris, pellet was

the least dominant type, accounting for 0.2% and 0.3%, respectively (Table 4). As to the colors, white plastic debris accounted

for the majority (55.3%) of plastic debris, with black being the least dominant color (5.1%). Specifically, the predominant color of

microplastics and large plastic debris was white (56.9%) and colored (40.9%; Table 5).

Out of 7951 visually sorted items, 905 items (11.4%) were selected and analyzed by the ATR–FTIR for their polymer compositions.

Among the selected items, 91.1% were identified as polymers (i.e. items with search score ≥0.7) and 2.2% were undefined items

(i.e. items with search score <0.7 but ≥0.6). Only 6.7% of the selected items were non-plastic, most of them consisted of paper,

cotton and animal wax, while the others were rejected items with a search score lower than 0.6. There was a total of 16 polymer

types identified, polystyrene (PS) was the predominant type (60.9%), followed by polyethylene (PE, LDPE, MDPE: 18.1%)

and polypropylene/ethylene propylene rubber (PP/EPR: 7.0%). Furthermore, other polymer types, including polypropylene (PP:

4.4%), ethylene propylene diene monomer (EPDM: 0.6%) and ethylene-vinyl acetate (EVA: 0.1%), were identified (Table 6).

N

18,123

N

2385

N

13,786

N

1,952

%

100

%

100

%

100

%

100

Size range (mm)

Total

5,3254,8475,2241,6381,089

0.355 – 0.4990.500 – 0.7090.710 – 2.7992.800 – 4.749

≥ 4.750

29.426.828.89.06.0

816594702167106

34.224.929.47.04.5

3,7353,5024,3421,357

850

27.125.431.59.86.2

774751180114133

39.738.59.25.86.8

Overall Tolo Channel Eastern Waters Western Waters

Table 3. Size distribution of plastic debris collected from Hong Kong waters.

Table 4. Type composition of microplastics and large plastic debris by number of items.

Table 5. Color composition of microplastics and large plastic debris by number of items.

Table 6. Types of polymer identified by the ATR-FTIR.

N

N

N

N

N

N

18,123

18,123

17,034

17,034

1089

1089

%

%

%

%

%

%

100

100

100

100

100

100

Plastic type

Color

Total

Total

7,4293,7163,1583,784

36

3,87010,0143,305

934

7,2133,1852,9443,659

33

3,6139,6832,860

877

216531214125

3

25733044557

Polystyrene foam (PF)Fibre (FB)Film (FL)

Fragment (FM)Pellet (PL)

TransparentWhite

ColoredBlack

41.020.517.420.90.2

21.455.318.25.1

42.318.717.321.50.2

21.256.916.85.1

19.848.819.611.50.3

23.630.340.95.2

Overall

Overall

Microplastics (0.355–4.749 mm)

Microplastics (0.355–4.749 mm)

Large plastic debris (≥4.750 mm)

Large plastic debris (≥4.750 mm)

A B C D E

N %Polymer composition

(1) Polyethylene (PE)(2) Low-density polyethylene (LDPE)(3) Medium-density polyethylene (MDPE)(4) Polypropylene (PP)(5) Polypropylene/ethylene propylene rubber (PP/EPR)(6) Polystyrene (PS)(7) Ethylene-vinyl acetate (EVA)(8) Ethylene propylene diene monomer (EPDM)Undefined itemsb

Non-plastic itemsc

Items scannedPlastic itemsa

132293

4063

55115

2061

905824

14.63.20.34.47.0

60.90.10.62.26.7

10091.1

Overall

21 22

4. Discussion and conclusion

5. Greenpeace Recommendations

This study revealed that Hong Kong waters are polluted by plastics. Our findings reported a mean

microplastic concentration of 2.936 ± 1.211 n/m3 in 2018 dry season, which was an order of magnitude

higher than a study conducted in Hong Kong waters in 2015 dry season (Cheung et al., 2018) and they reported

a mean microplastic abundance of 0.256 ± 0.092 n/m3. Compared with the microplastic abundance in different

regions reported in other studies, the level of microplastic concentration is also higher than other polluted regions,

including the South China Sea (Cai et al., 2018) and the coastal waters of East China Sea (Zhao et al., 2014; Table 7). Hong Kong waters are surrounded by plastic waste that is mostly generated by the city itself. Taking into account the high

percentage of polystyrene (PS) and polyethylene (PE) in the samples, this research reveals the severity of plastic pollution

originating from over-packaging. Government and Corporate action is needed immediately to tackle this issue.

Greenpeace calls on the government to develop a comprehensive action plan to reduce the use of single-use

plastics with ambitious targets and a clear timeline for implementation. Specifically, the government should

implement the following:

Greenpeace urges corporations to take immediate action to reduce unnecessary single-use plastics, including

packaging and to provide alternative delivery systems to customers without reliance on wasteful packaging.

Specifically, corporates should implement the following:

The spatial difference observed for microplastic

concentrations could be the result of rainfall during the

first week of sampling .Precipitation plays an important

role on the distribution of plastic debris in the marine

environment (Ivar do Sul et al., 2013) because the

translocation of land-based plastic debris to the marine

environment can be accelerated by rain and wind (Zhou

et al., 2015). Previous studies have shown that microplastic

densities were higher in the rainy season or after heavy

rainfall. A previous study by Cheung et al. (2018) found that

the mean microplastic concentration recorded in the rainy

season (6.124 ± 2.121 n/m3) was more than 23 times the dry

season (0.256 ± 0.092 n/m3) in Hong Kong surface waters.

Moore et al (2002) also reported a six-fold increase in the

number of plastic debris after a storm in the coastal waters of

southern California. These results indicate that precipitation

is a critical control on microplastic abundances. During the

sampling period of 7th and 8th January 2018 (i.e. when samples

were obtained from the Eastern waters), 16.2 and 11.6 mm

of daily rainfall was recorded respectively. According to the

Hong Kong Observatory (2018a), the monthly rainfall was

62.2 mm in January 2018, and sampling sites located in the

Eastern waters received precipitation with the range 20 to

30 mm on the 7th January 2018. However, sampling in the

Western waters was conducted from 12th to 15th January

2018, when no precipitation was recorded. This can perhaps

explain why the mean microplastic concentration was

significantly higher in the Eastern waters than in the Western

waters, and why it was higher than the result recorded in the

2015 dry season by Cheung et al. (2018). Nonetheless, this

study was conducted during the dry season and microplastic

densities recorded in one month cannot represent the annual

average. Therefore, a further survey accounting for the effect

of seasonality might be needed for a more accurate temporal

Table 7. Comparison of microplastic concentrations between this study and other regions. Data of this study is highlighted in bold.

Method Season Reference

Hong Kong coastal watersHong Kong coastal waters (2015)South China SeaCoastal waters of East China SeaPortuguese coastal waters

Density (n/m3 ± SEM)

Mesh size(μm)Study Area

Manta trawlManta trawlBongo Trawl

Neuston net trawlNeuston net trawl

2.936 ± 1.2110.256 ± 0.0920.045 ± 0.0930.167 ± 0.138

Range: 0.002–0.036

Dry seasonDry seasonDry season

Rainy seasonNot stated

333333333333280

This studyCheung et al., 2018

Cai et al., 2018Zhao et al., 2014Frias et al., 2014

and spatial distribution of microplastics in Hong Kong waters.

Microplastics were more abundant in the Eastern waters

than in the Western waters. The concentrations of

microplastics found in E1, E4 and E5 were the top three highest

among all 20 sampling sites, while microplastic concentrations

in the Western waters ranged between 0.191 and 0.895 n/

m3. This finding suggests that plastic debris in Hong Kong

waters could mainly come from terrestrial sources, such as

illegal dumping, sewage discharge, maritime transport and

industrial activities (Tsang et al., 2017).

Among the three investigated areas, Tolo Harbour has the

second highest mean density of microplastics as 2.344 ± 1.398

n/m3. Tolo Harbour is a shallow semi-enclosed water body which

is currently under local environmental threats from a wide range

of human activities, such as shipping, waste disposal, trawling

and fish farming (Owen & Sabdhu, 2000), and previous studies

have reported a higher microplastic densities in enclosed and

semi-enclosed areas (Barnes et al., 2009). Since Tolo Harbour

has long flushing time of 38 days in the dry season, the harbour’s

landlocked situation often leads to the natural stratification of the

water column. The long flushing time of Tolo Harbor means that

debris generated by rainfall events will easily be trapped (HKEPD,

2009), which in turn cause a relatively higher concentration of

plastic debris within the harbour.

In this study polystyrene foam was the dominant type

of microplastic (42.3%), and it accounted for 73.9%

of the white microplastics. Similarly, previous studies

conducted in Hong Kong also reported that polystyrene

foam was the predominant form of microplastic in the

surface waters (40.7%) during the 2015 dry season and on

beaches (92%) during the 2014 rainy season (Fok & Cheung,

2015; Cheung et al., 2018). Polystyrene foam is widely used

locally in food packaging and as protective packaging for

Limit and in the long run ban the use of single-use plastic, particularly those that are difficult to recycle, such

as disposable plastic tableware and disposable styrofoam containers. Implement a producer responsibility

scheme in order to reduce the single-use packaging materials directly from the source.

Establish ambitious targets with a clear timeline for reducing single-use plastics, going for ’reduction’ rather

than ‘recycling’ as the real solution to the issue.

Regularly monitor the microplastic concentration and distribution in Hong Kong waters, rivers and drinking

water. Disclose the results publicly and make all test data available for public discussion.

Reduce unnecessary packaging and invest in alternatives to single-use plastics: Many pre-packaged foods use

multilayer plastic packaging, which is commonly found in fruit, vegetables or gift boxes. Manufacturers and

retailers should immediately initiate reforms in product design and sales methods to reduce single-use plastics,

while putting in place plans to completely eliminate these and move to reusable or unpackaged forms.

With reference to examples already implemented in foreign countries, many food companies have set a 3-5 year

target to reduce the use of single-use plastics, and have redesigned product packaging to replace disposable

plastics with other materials. In the retail sector, it is also possible to set up a plastic-free area where customers

can purchase with their own containers or by using containers provided by retailers that can be returned.

Acknowledgement We acknowledge the support by the Greenpeace fleet Rainbow Warrior for sample collection. We are thankful to

Ms. Lui Ching Yee, Ms. Ng Wing Nam, Ms. Tsui Ka Mei, and Ms Chow Oi Chuen from The Education University of Hong Kong, Department

of Science & Environmental studies for their kind assistance in sample collection and analysis.

Establish a cross-sectoral collaboration platform to exchange views with community groups, the business

sector and other relevant stakeholders on a regular basis to promote the reduction of plastics.

Single-use plastic tableware should be eliminated but in the meantime, the fast food industry should adopt

policies to incentivise the use of reusable tableware, for example by providing discounts to customers who

request plastic-free take-away meals.

fragile items. Containers made with polystyrene foam are

cheap, lightweight and water and thermal resistant (Cheung

et al., 2018). In addition, transparent microplastics (21.2%)

were the second most abundant type found in Hong Kong

waters. Specifically, 55.8% and 28.5% of the transparent

microplastics were films and fragments, respectively.

This correlates with the common use of clear plastics in

plastic production, such as food packaging (Zhao et al.,

2014). More importantly, a regular monitoring program is

needed to see what actions should be taken in the future.

Government

Corporates

23 24

附錄 Appendix Locations and names of all sampling sites in Hong Kong.

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Name Latitude (°E) Longitude (°N)

Tolo Harbor

Eastern waters

Western waters

Site Sampling dateRegion

Tolo ChannelTolo ChannelTolo Channel

Chek Chau NorthChek Chau NortheastTung Ping Chau West

Cheung Tsui Chau SouthNorth Ninepin Island NortheastSouth Ninepin Island Southeast

Chung Hom Kok SouthwestLamma Island SoutheastLamma Island Southwest

Cheung Chau SouthSoko Island EastSoko Island East

Soko Islands WestFan Lau SoutheastFan Lau Northwest

Tai O SouthwestTai O Northwest

T1T2T3E1E2E3E4E5E6W1W2W3W4W5W6W7W8W9

W10W11

6th January 201813th January 20186th January 20186th January 20187th January 20187th January 20188th January 20188th January 20188th January 2018

13th January 2018 13th January 201813th January 201812th January 201812th January 201812th January 201812th January 201814th January 201814th January 201814th January 201814th January 2018

22.45305622.45344422.46911122.53025022.52144422.52633322.40119422.28830622.21691722.20313922.18525022.16983322.20541722.17327822.17186122.17080622.18866722.20402822.24333322.260944

114.245972114.276639114.300028114.353389114.390944114.422944114.407333114.367528114.435528114.211167114.172639114.094083114.017694113.953083113.951389113.886944113.873361113.844222113.834694113.846944

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Coordinate

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綠色和平是一個全球環保組織，致力於以 實際行動推動積極改變，保護地球環境與世界和平。

Greenpeace is a global, independent campaigning organization

that uses peaceful protest and creative communication to

expose global environmental problems and promote solutions

that are essential to a green and peaceful future.

研究團隊 Research Team

香港教育大學環境科學系：霍年亨博士、林詠玲、吳嘉洛、李憲杰、 呂靜宜、吳泳楠、徐家美、周藹銓

綠色和平東亞分部：楊令衠、賈柊楠

Department of Science & Environmental Studies, The Education University of Hong Kong:

Dr. FOK Lincoln, LAM Wing Ling, NG Ka Lok, LI Hin Kit, LUI Ching Yee, NG Wing Nam,

TSUI Ka Mei, and CHOW Oi Chuen

Greenpeace East Asia: YEUNG Ling Chun and JIA Zhong Nan

(852) 2854 8300 enquiry.hk@greenpeace.org www.greenpeace.org.hk

Greenpeace 綠色和平 - 香港網站 greenpeace_hk greenpeace_hk

綠色和平東亞分部 - 香港辦公室Greenpeace East Asia - Hong Kong Office