一項新出爐的研究報告顯示，為供應需求日增的全球鯊魚魚翅市場，每年有7300萬隻鯊魚遭到宰殺。這項數據是聯合國所獲知總捕捉量的3倍之多，顯示已全球的鯊魚生態造成相當大的衝擊，令人擔憂。
這項數據是首次根據鯊魚鰭獲數量之實際數據所做的估計。「鯊魚鰭(魚翅)交易是眾所皆知的秘密貿易，」報告的主筆作者莎莉‧克拉克(Shelley Clarke)表示，她是美國魚類科學家，主要在香港及日本工作。
研究團隊利用來自香港貿易商的一份獨立統計模組及資料，估算出目前在魚翅貿易裡的鯊魚數目。在轉換計算為鯊魚的重量後，得知總漁獲量數字高於聯合國糧農組織所公布的3到4倍以上。這份研究公布在本月的《生態學通訊》（Ecology Letters）裡。
最近鯊魚鰭交易量大增，所伴隨的關切也隨之升高，這些報告於焉而生。鯊魚其實很脆弱，加上成長速度慢，性成熟時間晚及後代數目不多，使得在過度捕撈下更容易受害，一旦變少，恢復物種數量速度也很緩慢。
再者，因為絕大多數鯊魚屬於海洋生物鏈的上層捕食者，過度捕捉鯊魚極可能造成被捕食者族群的瓦解，以及海洋生態系統全面失衡的情形。
人類主要補抓鯊魚使用其鰭，肉及肝油，不過鯊魚鰭的價值卻遠多於鯊魚肉。為了供應大量的鯊魚鰭，漁夫通常抓到鯊魚，割下魚鰭後，就將其身體扔回海中。
這些魚鰭主要輸入中國，作為魚翅羹料理用，一碗售價超過100美元。隨著中國中產階級人數增多，即使報告補抓到的鯊魚數量已經停滯不前或是變少，大家對這項佳餚的需求仍快速增長。
這份研究中提到關於鯊魚的一點好消息。上星期歐盟國會投票通過，決定從嚴管理歐盟鯊魚鰭的相關法規，該法規允許漁夫上岸切割魚鰭及魚身。
這個規定試圖預防鯊魚魚身被丟回海中，並規定魚鰭總重量不能超過總漁獲量的5％。歐盟漁業委員會要求將比例提高至6.5％，但國會也駁回該項建議，反而支持降低比例至2％的建議。
The world's rising demand for shark fins is killing as many as 73 million sharks a year, according to a new study. The figure is three times higher than the official catch number reported to the United Nations and raises concern that the trade is having a devastating impact on shark species worldwide.
The findings are the first estimates based on real data of the number of sharks harvested for fins. "The shark fin trade is notoriously secretive," said lead author Shelley Clarke, an American fisheries scientist based in Hong Kong and Japan.
The research team calculated the number of sharks represented in the fin trade using a unique statistical model and data from Hong Kong traders. After converting the figures to shark weight, they concluded the total is three to four times higher than shark catch figures reported to the UN Food and Agricultural Organization. The study was published in this month's edition of "Ecology Letters."
The findings come amid growing concern about the recent growth of the shark finning trade. Sharks are vulnerable animals and their slow growth, late maturity and small number of offspring make them especially susceptible to overexploitation, and the species is slow to recover once depleted.
Furthermore, because most sharks are top ocean predators, over-fishing of sharks is likely to cause disruption to prey populations and an overall imbalance in marine ecosystems.
Sharks are targeted directly for their fins, meat and liver oil, but the value of shark fins is often many times greater that of shark meat. To meet the demand for fins, fisherman frequently catch sharks, slice off the fins and discard the body at sea.
The fins are primarily exported to China for use in shark fin soup, which can command prices in excess of $100 a bowl. Demand for the delicacy has increased as the Chinese middle class has grown, even as reported global landings of sharks have remained static or declined.
The study does come amid a bit of good news for sharks. Last week the European Parliament voted to tighten the EU's shark finning regulations, which allow fishermen to land fins and carcasses separately.
The rules, intended to prevent shark carcasses being dumped at sea, mandate that the weight of fins as a proportion of the total catch not exceed 5 percent. The EU Fisheries Committee had called for the ratio to be increased to 6.5 percent, but the parliament rejected that recommendation in favor of decreasing the ratio to 2 percent.
