漁具纏繞是最致命危機 國際團隊繪製全球鯨魚遷徙地圖 籲加強合作護鯨 | 環境資訊中心
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漁具纏繞是最致命危機 國際團隊繪製全球鯨魚遷徙地圖 籲加強合作護鯨

2022年03月07日
環境資訊中心外電;姜唯 翻譯;林大利 審校;稿源:ENS

世界自然基金會(World Wildlife Fund, WWF)於2月20日世界鯨魚日發表了一份深入的鯨魚分布圖和報告,追蹤全球鯨魚的遷徙路徑、在公海的去向以及牠們所面臨各種累加的生存衝擊。

世界自然基金會於2月20日發表了一份深入的鯨魚分布圖和報告《保護藍色廊道》。圖片來源:Rémi Boudousquié/Unsplash

藍色廊道威脅日增 北大西洋露脊鯨僅餘336隻情況最危急

這份名為《保護藍色廊道》(Protecting Blue Corridors)的報告由奧勒岡州立大學、加州大學聖塔克魯茲分校和南安普敦大學等50多個海洋科學團隊合作,分析累積長達30年的科學資訊編撰而成。

從該分布圖中可看見全球845頭遷徙性鯨魚、透過衛星追蹤出的移動路徑。報告則說明鯨魚如何在其重要的海洋棲息地覓食、交配、分娩和照顧幼鯨,以及牠們在高速遷徙路徑(報告稱之為「藍色廊道」)沿線上,面臨了哪些多重且日益嚴重的威脅。

WWF鯨豚保育全球負責人強森(Chris Johnson)警告,人類活動的累積影響,正成為海洋物種危險甚至致命的阻礙。「截至目前,最致命的是漁具纏繞,每年估計造成30萬頭鯨魚、海豚和鼠海豚死亡。更糟糕的是,從北極到南極都有發生漁具纏繞死亡的案例。」

一隻雌性北大西洋露脊鯨和幼鯨。圖片來源:NOAA/維基百科

長達幾個世紀的商業捕鯨雖然已於1986年正式結束,但現在13種大鯨魚中仍有6種被世界自然保育聯盟(International Union for Conservation of Nature, IUCN)列為瀕危級(Endangered, EN)或易危物種。此外,儘管十多年前國際上就禁止商業捕鯨,但在世界各地的海洋中,鯨魚仍持續遭到獵殺。

鯨魚族群中存續狀態最危險的是極度瀕危的北大西洋露脊鯨,一種在加拿大和美國之間遷徙的物種。研究人員發現,該物種數量在過去10年間下降了30%,已來到20年來最低的336隻。

據估計,約86%被標記追蹤的露脊鯨,一生中至少被漁具纏繞過一次。根據新的分析,從2017年到2021年,加拿大和美國海岸有34頭北大西洋露脊鯨死於船隻撞擊或漁具纏繞。

全球鯨魚遷徙地圖 成為公海條約制定根據

報告作者之一、奧勒岡州立大學海洋哺乳動物研究所學者奧帕拉西奧斯(Daniel Palacios)說:「這是首次能夠繪製全球性的鯨魚遷徙地圖,並找出牠們的『超級高速公路』。」

「這張地圖將成為評估生物多樣性變化的重要海洋變量,並成為關鍵政策的根據,例如即將依《聯合國海洋法公約》制定的公海條約。」奧帕拉西奧斯說。

該報告也呼籲採用新的保護方法,並透過加強地方、區域和國際層面的合作來保護鯨魚。

其中最急迫的便是公海條約。聯合國將於3月根據《聯合國海洋法公約》完成公海新條約的談判。如果通過,公海條約將可以保護國家專屬經濟區以外地區的生物多樣性,並允許在公海建立海洋保護區。

加州大學聖塔克魯茲分校鯨魚生態學家、奧勒岡州立大學海洋哺乳動物研究所前副教授費蘭德(Ari Friedlaender),認為新的WWF地圖和報告非常有價值:「以研究人員的觀點,這份報告提供了以科學為本的圖解指南,能促進有效的管理和決策,幫助建立海洋保護區網絡,讓鯨魚更有機會茁壯成長。」

「保護藍色走廊的受益者絕不只是鯨魚。愈來愈多的證據顯示,鯨魚有維持海洋健康和保護全球氣候的重要作用,一條鯨魚捕獲的碳等同數千棵樹,」WWF的報告引用國際貨幣基金組織(International Monetary Fund, IMF)的估算指出,一頭大鯨魚的生態價值超過200萬美元,而WWF也估計,目前全球大鯨魚族群的總生態價值超過1兆美元。

Exploring Whale Superhighways With a Global Team of Scientists
GLAND, Switzerland, February 20, 2022 (ENS)

An in-depth new map and report that tracks whale migrations around the globe, highlights where the whales go in the high seas and the cumulative impacts they face has been issued by the World Wildlife Fund, WWF, to mark this year’s World Whale Day, February 20.

The report, “Protecting Blue Corridors,” was developed through collaborative analysis of 30 years of scientific data contributed by more than 50 research groups, with marine scientists from Oregon State University; the University of California, Santa Cruz; the University of Southampton and others.

The map provides a visualization of the satellite tracks of 845 migratory whales worldwide. The report outlines how whales are encountering multiple and growing threats in their critical ocean habitats – where they feed, mate, give birth and nurse their young – and along their migration superhighways, or blue corridors.

The cumulative impacts of human activities are creating a hazardous and sometimes fatal obstacle course for the marine species, warned Chris Johnson, the global lead for whale and dolphin conservation at WWF.

“The deadliest by far is entanglement in fishing gear – killing an estimated 300,000 whales, dolphins and porpoises each year. What’s worse, this is happening from the Arctic to the Antarctic,” Johnson said.

After centuries of commercial whaling, six out of the 13 great whale species are now classified as Endangered or Vulnerable by the International Union for Conservation of Nature, IUCN, even after decades of protection from commercial whaling, which ended formally in 1986.

But despite an international ban on commercial whaling since then, whales are still being hunted and killed across the world’s oceans. For a history of commercial whaling and the International Whaling Commission, click here.

Among whale populations most at risk is the critically endangered North Atlantic right whale, a species that migrates between Canada and the United States. This species is at its lowest point in 20 years – numbering only 336 individuals – a decline of 30 per cent over the past 10 years, the researchers learned.

About 86 percent of identified right whales are estimated to have been entangled in fishing gear at least once in their lives. Between 2017 and 2021, 34 North Atlantic right whales died off the Canadian and United States coasts from ship strikes and entanglement in fishing gear, according to the new analysis.

“Contributing years of data from Oregon State’s satellite tracking studies, pioneered by marine mammal researcher Bruce Mate, we see migrations across national and international waters creating conservation challenges for populations to recover,” said report co-author Daniel Palacios, an endowed associate professor in whale habitats with Oregon State University’s Marine Mammal Institute at the Hatfield Marine Science Center on Oregon’s coast.

“For a report of this nature, it was necessary to incorporate the data and expertise from many colleagues doing similar work in other parts of the world,” he said. “For the first time, we were able to map whale migrations on a global scale and identify their superhighways,” Palacios said.

“This map will become an essential ocean variable for a number of efforts working toward assessing changes in biodiversity and will inform critical policy initiatives like the upcoming Treaty for the High Seas under the United Nations Convention on the Law of the Sea,” he said.

“Protecting Blue Corridors” calls for a new conservation approach to address these mounting threats and to safeguard whales through enhanced cooperation on local, regional and international levels.

Of particular urgency is engagement with the United Nations, which is set to finalize negotiations on a new treaty for the high seas in March under the UN Convention on the Law of the Sea. If adopted, a high seas treaty could protect biodiversity in areas outside national Exclusive Economic Zones and allow for the creation of marine protected areas on the high seas.

Ari Friedlaender, a whale ecologist from University of California, Santa Cruz, and previously an associate professor at OSU’s Marine Mammal Institute, is convinced of the value of the new WWF map and report. “As a researcher, this report provides a visual science-based guide to help inform effective management and decisions to create networks of marine protected areas to ensure whales have every opportunity to thrive,” he said.

“The benefits from protected blue corridors extend far beyond whales. Growing evidence shows the critical role whales play maintaining ocean health and the global climate – with one whale capturing the same amount of carbon as thousands of trees,” according to the WWF report.

The International Monetary Fund estimates the value of a single great whale at more than $2 million, which, WWF estimates, totals more than $1 trillion for the current global population of great whales.

※ 全文及圖片詳見:ENS

作者

姜唯

如果有一件事是重要的,如果能為孩子實現一個願望,那就是人類與大自然和諧共存。

林大利

於特有生物研究保育中心服務,小鳥和棲地是主要的研究對象。是龜毛的讀者,認為龜毛是探索世界的美德。