底拖網捕魚5個可怕之處

專題報導 - 2016-07-20
「底拖網」又稱「海洋推土機」,顧名思義,是將魚網沉至海床拖行,是工業化捕魚船上的重型捕撈工具,極具破壞力,頃刻間能將無數海中生物一網打盡、珊瑚化為烏有。底拖網每次出動均掠奪大量魚獲。您有否想過餐桌上的美味海產,很有可能是來自危害海洋生態的底拖網?

今年5月,連鎖快餐店麥當勞和一些來自挪威及俄羅斯的大型漁業企業宣佈,在各地政府協議將部份北極水域劃為海洋保護區之前(包括禁止底拖網捕魚橫行海洋和勘探石油),也不會將捕魚範圍,進一步擴張至挪威以北、毗鄰北冰洋的巴倫支海(Barents Sea)。

到底「底拖網」有幾可怕?

1. 過度捕撈

每年有數以百萬噸計的海洋生物,遭底拖網吞噬。其所經之海床,生命殆盡,難以復元如初。因此,各地政府必須儘快禁止底拖網,否則海洋生態岌岌可危。

Sea birds following German flagged trawler Maartje Theadora, controlled by the Dutch company PFA (Pelagic Freezer Association) fishing for Herring in the English Channel around November and December every year during the Autumn Spawning. Greenpeace is documenting the discard of bycatch in the English Channel claiming many of these monster boats are highgrading their catch, discarding parts of it to increase its market value. Official reports of former fishing activities reveal how one vessel in one single trip dumped up to 600 tonnes of fish, the equivalent to 2 million meals.

2. 混獲

千萬別要誤會使用底拖網捕魚方法,可令魚獲豐富。事實上,網內數量龐大魚獲中,無數物種只是遭誤捕,例如海鳥,甚至已屬近危物種的黑鯊,就是混獲下的犧牲者;一些魚苗則由於無甚市場,難逃被棄掉命運;而大部份被誤捕的魚,往往不是死掉,便是奄奄一息,同樣被棄回大海。

3. 動搖海床

要將魚網沉到海床拖行,魚網本身必須有一定重量。一個底拖網,可達三層樓高,更大如足球場。可想而知,被底拖網掃過的海床會變成怎樣?許多藏在深海的海床,水流與氣溫偏低,生態穩定自然,可是一旦遇上底拖網,寧靜和平的生態蕩然無存。

4. 危害珊瑚

不僅位處熱帶的海洋,才見珊瑚,許多珊瑚品種均棲身冰冷的深海之中,有些更存活數千年之久,但如果被「海洋推土機」輾過,數秒間便會化為烏有。以佛羅里達和紐西蘭為例,有97%至99%的深海珊瑚被底拖網破壞(State of the World’s Oceans, 2009, Springer)。

Fishing vessel Adrar is discarding an estimated 60 tonnes of sardines outside Dahkla. According to the watchdog NGO Western Sahara Resource Watch a total of 1000 tonnes of fish is said to have been discarded by Adrar alone during 2013.A new Greenpeace report, Exporting Exploitation: How retired EU fishing vessels are devastating West African fish stocks and undermining the rights of local people, shows how both EU fishing and Norwegian  vessels are being exported to fish in the controversial waters of the territory of Western Sahara, occupied by Morocco.Adrar was exported from Norway to a Moroccan company operating in Western Saharan waters early in 2013. Before the export the Fishing vessel was refurbished in Fiskebäck on the Swedish west coast.

5. 摧毀無數海洋生物的家園

海床是許多海洋生物如海膽、海筆、海綿、蚌類、蠕蟲及蛤蜊等海洋生物的家園,一些更隱沒海床洞穴之內。底拖網的出現,迫使牠們失去家園,甚至死亡。

或許有人認為,深海或浮游生物與己無關,但食物鏈環環緊扣,某些海洋生物正是其他魚類或蟹類的食物來源,食物鏈一旦中斷,您我常吃的海產也難以存活。底拖網有如把樹根連根拔起,影響整棟樹的健康。

給海洋喘息

地球不是人類獨享,人類必須與大自然包括所有動植物共生。可是人類為一己之利,不惜破壞環境,掏空天然資源。長久以來,壯闊海洋孕育饒富的生命力,但過去數十年,人類將底拖網帶入海洋,受害不只海洋生態,還有您我的下一代與未來。

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