For 3 billion people around the world, seafood provides a significant source of protein and nutrition. But recent studies show that 33% of wild fisheries are overfished, while another 60% are fished at their maximum capacity. In fact, over half the seafood we eat– from finfish and shellfish to seaweed and algae– isn’t caught in the wild. It’s grown through aquaculture, or aquatic farming. Farmed seafood is one of the fastest-growing food industries, expanding in volume by 5.8% each year. But different methods of aquaculture come with different advantages and issues– some of which echo the serious problems we’ve seen in industrial agriculture. So how can we avoid repeating the mistakes we’ve made on land, at sea? What aquaculture approaches are we currently using, and what does a sustainable way to farm the ocean really look like?
對全世界三十億人而言, 海鮮是重要的蛋白質和營養來源。 但近期的研究顯示, 33% 的野生漁場被過度捕撈, 另外 60% 也已經 被捕撈到最大極限。 事實上,我們吃的海鮮中 有一半以上—— 從有鰭魚類到有殼魚類、 水草、海藻—— 並不取自野生的大自然。 它們的來源是水產業或水產養殖。 養殖海鮮是成長 最快速的食物產業之一, 每年成長量有 5.8%。 但水產業的不同方法, 會有不同的好處和議題—— 當中有一些,也反應出了我們 在工業化農業中看到的重大問題。 所以,我們要如何避免在海中 重蹈在陸地上的覆轍? 我們目前在使用的 水產業方法是什麼? 能在海洋中做到永續 養殖的方法是什麼樣子的?
One of the most common aquaculture methods involves large pens made of nets, where fish are farmed offshore in floating cages roughly 1000 square meters in size. Commonly employed off the coast of Chile and in the fjords of Norway, these fish, like many industrially farmed animals, occupy stressful, overcrowded pens. They produce massive amounts of waste, polluting the surrounding areas and potentially spreading diseases to wild species. Worse still, since the antibiotics employed to fight disease aren’t fully absorbed by the fish, they get excreted back into the environment. Net pens are also susceptible to escapes, unleashing huge numbers of fish which compete for resources and weaken the local gene pool with genes adapted for captivity. Escaped fish can even disrupt local ecosystems as invasive species.
最常見的水產方法之一, 用到網子製成的圍欄, 讓一千平方公尺的籠子漂浮在 近海中,再將魚類養殖在籠子中。 常見這種方法的地方, 包括智利沿海以及挪威峽灣, 這些魚類就像是 被工業化飼養的動物一樣, 被關在過度擁擠 且壓力很大的圍欄中。 牠們會產生大量的廢物, 污染到周圍區域, 還有可能會傳播疾病給野生物種。 更糟糕的是,因為用來 對抗這些疾病的抗生素 沒有完全被魚類吸收, 會再被排泄到環境中。 網狀圍欄也很容易逃脫, 釋放出大量的魚類,增加資源競爭, 適應了囚禁生活的基因 會造成當地的基因庫變弱。 逃脫的魚類甚至可能成為入侵 物種,造成當地生態系統的混亂。
Other techniques, such as man-made coastal ponds commonly used for shrimp farming in Southeast Asia, create additional environmental problems. Just like net pens, these ponds are prone to spreading pollution and disease. Their construction also frequently destroys important ecosystems like mangroves and marshes, which protect coastal areas from storms, provide habitats, and absorb tons of greenhouse gases.
其他技術, 比如在東南亞常會使用 人造沿海池塘來養殖蝦子, 創造出額外的環境問題。 就像網狀圍欄一樣,這些池塘 很容易就會散播污染和疾病。 建造這些池塘時,經常也會 摧毀重要的生態系統, 比如紅樹林和沼澤, 它們的功能包括協助 海岸地區抵禦暴風雨、 提供棲息地,以及吸收 數公噸的溫室氣體。
One way to solve these problems is to farm fish on land in completely contained systems. Tanks and raceways can recirculate and filter water to prevent pollution. But even fully contained facilities still contend with another major hurdle: fishmeal. About 10% of the seafood caught globally is used to feed animals, including carnivorous farmed fish. Researchers are working on fish feed made of insects and plant-based proteins, but for now many inland fish farms are connected to overfishing.
解決這些問題的其中一種方法, 就是在陸地上養殖魚類, 且是在完全被控制的系統中養殖。 貯水池和水溝可以協助水的 再循環和過濾,避免污染。 但即使是完全受控制的設施, 仍然要對付另一個巨大的障礙: 飼料魚粉。 全球捕捉到的海鮮 有 10% 會被用來餵食動物, 包括養殖的肉食性魚類。 研究者在研究用昆蟲 及植物性蛋白質所製成的魚飼料, 但現在許多內陸魚類養殖場 也和過度捕撈有關。
All these obstacles can make sustainable aquaculture feel a long way off, but innovative farmers are finding new ways to responsibly farm the seas. The most promising solution of all may be to look lower on the food chain. Instead of cramming large, carnivorous fish into pens, we can work with natural ocean systems to produce huge amounts of shellfish and seaweeds. These low-maintenance flora and fauna don’t need to be fed at all. In fact, they naturally improve water quality, filtering it as they feed off of sunlight and nutrients in the seawater. By absorbing carbon through photosynthesis, these farms help battle climate change, and reduce local ocean acidification while creating habitats for other species to thrive.
所以這些障礙,讓永續水產業 感覺好像遙不可及, 但創新的養殖業者在想新辦法, 以更有責任地在海中進行養殖。 最看好的解決方案, 可能是要轉向食物鏈的更下層。 要做的不是把大型 肉食性魚類擠到圍欄中, 我們可以運用大自然的海洋系統 來產出大量的有殼魚類和海草。 這些需求標準不高的植物群 和動物群,完全不用餵食。 事實上,它們會很自然地改善水質, 因為當它們從太陽光和海中 營養物取食時,就會過濾海水。 透過光合作用吸收碳, 這些養殖場就能對抗氣候變遷, 減輕當地的海洋酸化, 同時為其他物種 創造出棲息地來成長茁壯。
Shifting to restorative ocean farming could provide good jobs for coastal communities, and support healthy plant and shellfish-based diets that have an incredibly low carbon footprint. In just 5 months, 4,000 square meters of ocean can produce 25 tons of seaweed and 250,000 of shellfish. With the right distribution network, a series of small farms, collectively the size of Washington State could feed the planet. Farms like these are already popping up around the globe, and a new generation of farmers is stepping up to pursue a more sustainable future. Done properly, regenerative ocean farming could play a vital role in helping our oceans, our climate, and ourselves.
改使用恢復性海洋養殖, 能為海岸社區提供好工作機會, 並支持健康的植物 和有殼魚類製的食物, 它們的碳足跡都非常低。 不出五個月,四千平方公尺的海洋 就能產生出二十五公噸的海草, 以及二十五萬隻有殼魚類。 只要能正確地分佈網路, 僅需要總面積加起來跟華盛頓州 一樣大的一系列小養殖場, 就能供給食物給全球。 在全球各地已經開始 出現這類養殖場, 新世代的養殖業者開始站出來, 追求更永續的未來。 如果做得妥當,再生式海洋養殖 能扮演關鍵的角色, 協助我們的海洋、氣候, 以及我們自身。