掃走垃圾 「吉」出更多海洋空間｜Fighting oceans pollution for new placemaking opportunities
香港「地少人多」，一直以來我們只討論土地問題，把焦點放在陸上的資源分配，很少關注海洋資源。但香港海面的面積，其實比陸地大，面積有1,650平方公里。除了填海、船運，吉人其實可以有更廣闊的想像，例如如何把海洋營造出更好的公共空間，甚至發掘海洋特性以解決土地問題。不過，營造之前，我們或許需要先正視海洋垃圾的問題。
香港的海有多大？
香港陸地面積為1,104平方公里，海面面積則稍大，為1,650平方公里，相等於兩個新加坡的面積還要大；海岸線長達1,189公里，相當於香港與馬尼拉的直線距離，沿岸地區人口密集，不少海洋垃圾屬人為因素而來。
海洋垃圾量驚人
2014年，政府收集的海上垃圾量約為15,200公噸，相等於可裝滿逾580個40呎貨櫃。負責清理的，主要有4個政府部門，包括收集超過7成垃圾量的海事處，還有康文署、漁護署與食環署。
八成海洋垃圾來自陸上
香港的海洋垃圾，可大致分為三類：油污、漂浮垃圾、海底垃圾。當中漂浮垃圾的種類繁多，包括有天然物料如樹枝和海藻、人造物料如飲品樽和漁農業用的大型發泡膠箱等。2013年，環保署的研究結果反映，在香港海域的海上垃圾有逾95%源於本地，80%來自陸上活動，而產生最多垃圾的陸上活動，則是「岸邊及康樂活動」，包括大量飲品樽、食物包裝等。
垃圾也分時令
香港的海洋垃圾量，夏季比冬季更多，原因夏天降雨和颱風較多，有很多垃圾沖到大海，加上夏天多人到泳灘進行水上活動。環保署的研究反映，節日後的海洋垃圾也會增多。
地理分佈
離島、海港東、海港西、香港南及九龍西，是漂浮垃圾的重災區
生活層面：即棄塑膠、洗衣機污水
海洋垃圾來源廣泛，不止大型活動如工業、漁業，活在城市裡的我們，也應負上責任。日常生活中使用即棄餐具，有機會積聚垃圾最終流到大海。最近美國查爾斯學院一項研究發現，家居污水也是一大來源，因為在洗衣過程中，可導致衣物上的人造纖維脫落，禍害海洋。
城巿層面
城巿的排水系統、基建設計也是重要一環。雖然雨水收集口、路邊雨水渠、明渠等，已安裝了欄柵避免垃圾進入渠道系統，在大雨或颱風時，部分垃圾可沿經渠導沖出大海。除了人造的排水系統，河溪也是漂浮垃圾的入海途徑，例如環保署就發現，大雨過後，有河溪流經的貝澳泳灘、洪聖爺灣等會發現較多垃圾。
另外，大型的產業活動，也會造成大量海洋垃圾，例如漁船、養魚作業的繩索、浮標、破漁網等，是常見垃圾之一。至於海泥傾倒，更是影響海洋的龐大人為活動，這些海泥源自於大型基建工程，包括防洪、填海，當中產生的海洋沉積物需要妥善處理。香港現今的做法是，未受污染的海泥會運到長洲以南、果洲群島以東或東龍州以東的卸置區傾倒，受污染的則送至東沙洲的密封式海上卸署設施填理。
世界層面
1997年，美國海洋學家Charles Moore從夏威夷乘船到加州長灘時，發現太平洋環流中有一片巨大的垃圾堆在海中心漂流，面積近160萬平方公里，相等於1,446個香港。因為塑膠垃圾無法分解，這些垃圾聚積於海洋環流中，形成垃圾帶。最可怕的是，地球上不止一個大型海洋環流，如此驚人的垃圾帶，恐怕也出現在北大西洋與南大西洋環流、印度洋環流等。
繪圖: Garrick Chan
相片來源：網上圖片
地點：香港
Fighting oceans pollution for new placemaking opportunities
For a densely populated small city like Hong Kong, land scarcity is arguably a never-ending challenge. While the issue seems burning and unsolvable, a paradigm shift of exploring solutions from the sea resources could be a way to go. Hong Kong’s sea area is indeed larger than its land. If we try putting on a more imaginative lens to challenge the status quo of reclamation, the sea area might be able to help releasing the pressure of land shortage in a whole new way. As fellow GUTMANS is ready to dive into this untouched realm of placemaking, there comes the immediate challenge – marine debris.
How big is the Hong Kong sea?
As big as twice of the size of Singapore, Hong Kong’s sea area is about 1650 square kilometres, slightly larger than its land by 546 square kilometres. With a lengthy costal line of 1189 km, equivalent to the distance between Hong Kong to Manila, marine debris from land-based source is one of the major causes of ocean pollution.
The dirty facts of marine pollution
According to official figures in 2014, Hong Kong has cleared up around 15,200 tonnes of litter from the sea by the 4 related government departments. To put it in concrete terms, such amount of trash could fill up 580 40-feet containers.
80% marine trash originated from the city
Hong Kong’s marine debris are mostly oil spill, floating and seabed waste. The most common floating trash include natural materials such as tree branches and seaweed, and man-made materials such as beverage bottles and foam boxes. A research from the Environmental Protection Department in 2013 indicated that 95% of marine floating garbage were generated locally, while 80% originated from human activities on the land, such as plastic bottle and food packaging.
More marine trash found in Summer
Hong Kong has a sub-tropical climate where summer is rainy and with occasional typhoons. The weather and the frequent outdoor water activities combine to pose extensive negative impact to marine pollution by flooding more garbage to the sea during summertime. Research from Environmental Protection Department indicated that more marine trash could be found after festivals.
Floating garbage’s whereabouts
Hong Kong sea area around outlying island, east and west of the harbour, southern Hong Kong and West Kowloon are heavily polluted by floating garbage.
Pollution from household: single-used plastic, domestic sewage
Besides industry and fishery waste, domestic waste from the city also heavily impact marine pollution, for instance, the extensive use of single-used cutlery could end up being plastic waste in the ocean. A recent research from the College of Charleston in the US reveals that one of the main sources of plastic waste from household comes from washing machines, as laundering gradually breaks down synthetic fabric and eventually polluting the ocean.
How city waste enters the sea
In times of heavy rain, the drainage system of a city indirectly sends tonnes of garbage together with the rainwater to the sea. On the other hand, river is another major pathway of ocean plastic waste. The Environmental Protection Department observed that more rubbish travelled to Pui O Beach and Hung Shing Yeh Bay where rivers and streams flow through after heavy rain.
In addition, large-scale industrial activities such as fishery, infrastructure construction dispose broken fishing ropes, buoys, fishing nets to the and dredged mud poses imminent threat to ocean pollution especially when the sediment is not treated properly.
Ocean waste in global perspective
In 1997, marine researcher Charles Moore discovered an enormous stretch of floating plastic debris which was subsequently named as the “Great Pacific garbage patch”. Located between Hawaii and California, the garbage patch covers an estimated surface area of 1.6 million square kilometers, an area equivalent to 1446 times of Hong Kong. As conventional plastic is not biodegradable, it eventually breaks into smaller pieces where currents converge them into “garbage patch” through ocean gyre. Worse still, there are 5 gyres in the world oceans, circling patches of marine trash at the North and the South Pacific Ocean, and the Indian Ocean. They will definitely become bigger and bigger if we do not stop feeding them with plastic waste day by day.
Illustrator: Garrick Chan
Photo source: Internet
Location: Hong Kong
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