Great Barrier Reef Suffers Another Massive Bleaching
VOA News｜Science & Health
April 07, 2020 06:45 AM (source)
Great Barrier Reef Suffers Another Massive Bleaching
April 07, 2020 06:45 AM
The Great Barrier Reef off the coast of Australia is suffering its third mass bleaching event in five years, but the current global health pandemic has pushed the news of the major environmental crisis onto the back burner.
New scientific data, confirmed by Australia's Great Barrier Reef Marine Park Authority, shows ample evidence that overheating of the ocean is causing new damage along the world's largest coral reef system.
The barrier reef takes up an area of about 344,000 square kilometers in the Coral Sea, off the coast of Queensland, Australia. A third of the corals in the reef perished after the 2016 heat wave. Another heat wave hit in 2017.
Coral live in a symbiotic unity with algae, which convert sunlight into food for the coral polyps and give the corals their distinctive color. The brightly colored coral islands, or atolls, are visible from an airplane.
When the water temperature rises by as little as 1 degree Celsius, the corals expel the algae and begin to starve. They survive for some time, but they lose color and become fragile and susceptible to disease.
The world's oceans absorb most of the heat resulting from carbon emissions produced by humans, and the oceans are warming faster than expected. The year 2019 was the hottest on record for the world's oceans. February, which is summertime in Australia, was the warmest month on record for water temperatures near the reef.
The Great Barrier Reef has had five major bleaching episodes since 1998, but the first few were further apart.
Jodie Rummer, marine biologist from James Cook University in Australia, was part of an international team of scientists who tracked wild populations of five species of coral reef fish before, during and after the 2016 heat wave. She said the team was surprised to find that water temperatures in February four years ago were much higher than expected.
"We were collecting fish in the shallow lagoon off the research station, and our dive computers read that the water temperature was 33°C," she wrote in The Conversation US online academic journal. "We looked at each other. These are the temperatures we use to simulate climate change in our laboratory studies for the year 2050 or 2100."
Scientists say the latest data show that this year's bleaching is second only to the 2016 episode. However, it was more widespread and affected the southern end of the reef, which was spared before. There are concerns that the rising water temperatures around the reef will make bleaching an annual occurrence.
In the past 20 years, much has been written about the destruction of the Great Barrier Reef and its consequences for marine life and for humanity. Environmentalists are becoming frustrated with what they see as a lack of action to prevent coral bleaching from recurring. With authorities worldwide engaged in battling the coronavirus pandemic, there is growing fear that coral reef disease may not get the attention it needs, especially among people who live far away from it.
On the northern shores of the Adriatic Sea, Croatian fishermen hold on to an old adage: "If you stick your finger into the sea, you are connected with the whole world."
Scientists warn that the coral decay is a bad omen for fish and other marine creatures that are an indispensable part of the food chain. They say many species won't have time to adapt to the accelerating rise of water temperatures.
澳洲（Australia）大堡礁（Great Barrier Reef）正面臨一場大規模的白化(bleaching，註 1)危機，這也是近 5 年來第 3 次受創，但受到全球流行病(pandemic)影響，這起重大環境危機被新聞擱置(push the news onto the back burner)。
大堡礁海洋公園管理局（Australia's Great Barrier Reef Marine Park Authority）的最新科學數據提供充分(ample，註 2)證據，顯示因為海水溫度過高，導致全世界最大的珊瑚礁(coral reef)遭受破壞。
坐落在澳洲的昆士蘭州（Queensland）海岸，珊瑚海（The Coral Sea）的珊瑚礁面積約為 344,000 平方公里，2016 年的熱浪導致有三分之一的珊瑚死亡(perish，註 3)，2017 年接連又發生熱浪。
只要海水溫度上升 1 度，珊瑚會將海藻排出且餓死，雖還可能存活一段時間，但珊瑚會失去原本繽紛的色彩，變得脆弱(fragile，註 4)且容易感染(susceptible，註 5)疾病。
全球海洋吸收大部分人類碳排放(carbon emissions)所產生的熱能，而海洋升溫的速度比預期還要高： 2019 年海洋溫度是全球海洋溫度最高的一年，二月正值澳洲夏季，鄰近珊瑚礁的海水溫度已來到新高。
自 1998 年以來，大堡礁出現五次白化事件，但前面幾次間隔時間較長。
澳洲詹姆士庫克大學（James Cook University in Australia）的海洋生物學家茱蒂．魯默（Jodie Rummer）曾參與跨國科學研究，追蹤分析 2016 年熱浪前後五種珊瑚魚的野生族群增長。她的團隊意外地發現了該年二月份的海水溫度遠高於預期。
「當時我們在研究站外的環礁淺湖(lagoon)內蒐集珊瑚魚，潛水錶顯示海水溫度已經來到攝氏 33 度，我和團隊夥伴彼此對望，這樣的溫度是實驗室在模擬(simulate) 2050 年至 2100 年間氣候變遷才會發生的。」她在美國線上學術期刊寫道。
科學家表示，根據最新的數據，雖然今年的白化只是 2016 年以來的第二起，但此次受影響範圍較廣，珊瑚礁南岸也無法倖免。他們擔心珊瑚附近海域持續升溫，白化事件恐怕將年年上演。
在亞得里亞海（the Adriatic Sea）的北岸，克羅埃西亞的（Croatian）漁民流傳一句古老的諺語(adage)：「將手指伸入大海，就與全世界相連。」
註 1： bleaching 由動詞 "bleach"「漂白；使褪色」與動名詞字尾 "-ing" 組成，意指「白化」
註 2： ample 於本文指「足夠的，充足的，充裕的」；本字也常指「（身軀）肥大的，粗壯的，豐滿的」
註 3： perish 於本文指「死亡；毀滅」；本字也常指「脆裂，老化」
註 4： fragile 於本文指「脆弱的」；本字也常指「易損壞的；易碎的」
註 5： susceptible 於本文指「易受影響的，易受傷害的」；本字也常指「（尤指想法或陳述）能被理解（或證明、解釋）的」；注意重音在第 2 音節
註 6： indispensable 由表示「不，無，非」的字首 "in-" 與表示「可有可無的，非必需的」的形容詞 "dispensable" 組成；注意重音在第 3 音節
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Check your comprehension!
Choose the BEST answer to each of the questions below. After you finish, highlight the parentheses to reveal the hidden answers.
1. ( A ) What can be inferred from this passage about the role of algae in a symbiotic system with coral?
(A) Algae gives coral reefs their color.
(B) Algae absorbs carbon dioxide produced by coral.
(C) Algae provides coral with a shelter.
(D) Algae causes the water temperature to decrease.
2. ( A ) According to the passage, all of the following are true of many critical consequences of overheating EXCEPT?
(A) The weakening of coronavirus pandemic.
(B) The disappearance of corals' color.
(C) A frequent occurrence of bleaching.
(D) A life-threatening influence on corals.
3. ( C ) Why does the author mention a saying from Croatian fishermen?
(A) To show how fishermen contribute to the existence of marine creatures.
(B) To explain why sticking fingers into the sea is a key to combatting bleaching.
(C) To emphasize the importance of taking action to preserve the Great Barrier Reef.
(D) To help explain the significance of marine conservation in Croatia.