1995年以來,澳大利亞大堡礁珊瑚減少逾50%大綱

Australia's Great Barrier Reef has lost More than half of its corals since 1995 due to warmer seas driven by climate change, a study has found.

研究發現，自1995年以來，由於氣候變化導致海洋變暖，澳大利亞大堡礁的珊瑚損失了一半以上。

Scientists found all types of corals had suffered a decline across the world's largest reef system.

科學家發現，在全球最大的珊瑚礁羣大堡礁中，所有類型的珊瑚都在減少。

The steepest falls came after mass bleaching events in 2016 and 2017. More mass bleaching occurred this year.

尤其在2016年和2017年大堡礁發生大規模珊瑚白化後，珊瑚數量銳減，今年也出現了更大規模白化現象。

"There is no time to lose - we must sharply decrease greenhouse gas emissions ASAP," the researchers said.

研究人員說：“我們必須抓緊時間，儘快大幅減少溫室氣體排放。”

The study, published in the journal Proceedings of the Royal Society B, was conducted by marine scientists at the ARC Centre of Excellence for Coral Reef Studies in Queensland.

研究報告發表在英國《皇家學會報告：生物科學》期刊上，是由昆士蘭州ARC珊瑚礁研究卓越中心的海洋科學家進行的。

Scientists assessed the health and size of coral colonies across the reef from 1995 to 2017.

科學家們評估了1995年到2017年大堡礁珊瑚羣的健康狀況和大小。

They found populations had dropped by more than 50% in all coral sizes and species, but especially in branching and table-shaped corals.

他們發現，無論珊瑚的大小和種類，所有珊瑚的數量都損失了一半以上，尤其是分枝和桌形珊瑚。

These are the large, structural species which usually provide habitats for fish and other marine life.

珊瑚礁是大型的結構物種，通常爲魚類和其他海洋生物提供棲息地。

Prof Terry Hughes, a study co-author, said these coral types had been "worst affected" by the back-to-back mass bleachings which damaged two-thirds of the reef.

研究合著者、特里·休斯教授說，這些珊瑚類型受到了連續不斷的大規模白化“最嚴重影響”，三分之二的珊瑚礁遭到了破壞。

Bleaching occurs when corals under stress drive out the algae - known as zooxanthellae - that give them colour.

當珊瑚在壓力下驅逐了爲它們帶來顏色的藻類（稱爲蟲黃藻）時，就會發生白化。

Corals can recover if normal conditions return, but it can take decades.

如果情況恢復正常，珊瑚可以自我修復，但需要數十年時間。

A study in 2019 found that damaged coral colonies had struggled to regenerate because most of the adult corals had died.

2019年的一項研究發現，由於大多數成年珊瑚已經死亡，受損的珊瑚羣體很難再生。

"A vibrant coral population has millions of small, baby corals, as well as many large ones," said lead author Dr Andy Dietzel.

研究報告的主要作者安迪·迪策爾博士說：“一個充滿活力的珊瑚種羣中有數百萬個小的珊瑚幼蟲和很多大珊瑚組成。”

"Our results show the ability of the Great Barrier Reef to recover - its resilience - is compromised compared to the past, because there are fewer babies, and fewer large breeding adults."

“我們的研究結果表明，大堡礁的恢復能力與過去相比已經有所下降，因爲珊瑚幼蟲和較大的繁殖成蟲都減少了。”

Last year, the Australian government's official agency on the reef confirmed that human-driven warming remained the biggest threat to the reef's long-term survival.

去年，澳大利亞政府負責大堡礁的官方機構證實，人類活動導致的氣候變暖仍然是大堡礁長期生存的最大威脅。

Stretching over 2,300km, the reef was designated a World Heritage site in 1981 for its "enormous scientific and intrinsic importance".

大堡礁綿延2300公里，因其“巨大的科學和內在價值”，於1981年被列爲世界遺產。

But in the past decade in particular, it has been vastly damaged by warmer seas which have killed off coral, dispersed other sea life and sped up growth of algae and other contaminants.

但特別是在過去的十年裏，海水變暖使珊瑚死亡和其他海洋生物分散，導致海藻和其他污染物迅速增多，大堡礁受到了極大的破壞。

"We used to think the Great Barrier Reef is protected by its sheer size - but our results show that even the world's largest and relatively well-protected reef system is increasingly compromised and in decline," said Prof Hughes.

休斯教授說：“我們過去一直認爲由於面積寬廣，大堡礁受到了保護，但我們的研究表明，即使是世界上最大的、保護相對良好的珊瑚礁系統也在日益受到威脅，並且在衰退。”

In March, scientists reported the reef had suffered its third mass bleaching event in five years. The full scale of the damage was still being assessed.

今年3月，科學家報告稱，大堡礁遭遇了五年來的第三次大規模白化。整個損失規模仍在評估中。

Global temperatures have already risen by about 1C since pre-industrial times. The UN has warned that if that rise reaches 1.5C, 90% of the world's corals will be wiped out.

全球的溫度相較於工業時代前已上升了1攝氏度。聯合國曾警告稱，若溫度升高1.5攝氏度，全球90%的珊瑚都將消失。