Fish key to reef climate survival
By Richard Black
Environment correspondent,
By Richard Black
Environment correspondent,
BBC News website
A healthy fish population could be the key to ensuring coral reefs survive the impacts of climate change, pollution, overfishing and other threats.
健康合理的魚群數量可能是確保珊瑚礁在氣候變遷、環境污染、過度捕撈及其他威脅等各種衝擊下存活的關鍵因素。
Australian scientists found that some fish act as "lawnmowers", keeping coral free of kelp and unwanted algae.
澳洲的科學家們發現一些魚類著實扮演了"除草機"的角色，使珊瑚礁得以避開巨藻以及多餘海藻的糾纏。
At a briefing to parliamentarians in Canberra, they said protected areas were rebuilding fish populations in some parts of the Great Barrier Reef.
在對坎培拉國會議員做的簡報中他們表示，在部份大堡礁的保護區域中已重建魚群數量。
Warming seas are likely to affect the reef severely within a few decades.
最可能在短短幾十年間嚴重地影響珊瑚礁的就是海洋的暖化。
Pollution is also a growing problem, particularly fertilisers that wash from agricultural land into water around the reef, stimulating the growth of plants that stifle the coral.
環境污染也是一個日益嚴重的問題，特別是由耕地上所使用的肥料被沖刷到珊瑚礁附近的水域後，刺激植物的生長進而使珊瑚窒息。
Protect and survive
The assembled experts told parliamentarians that fish able to graze on invading plants played a vital role in the health of reef ecosystems.
前來參加會議的專家告訴國會議員，能夠吃掉大批入侵植物的魚群，對珊瑚礁生態系統的健康狀態扮演了不可或缺的角色。
"The Great Barrier Reef is still a resilient system... and herbivorous fish play a critical role in that regenerative capacity, by keeping the dead coral space free of algae, so that new juvenile coral can re-establish themselves," said Professor Terry Hughes from James Cook University in Townsville.
"大堡礁仍舊是一個具有彈性及恢復力的系統，這些草食性的魚類對再生能力起了關鍵性的作用，牠們使海藻無法佔據在已死去的珊瑚上，因此新生的珊瑚可以在上頭生長，" Terry Hughes這位來自Townsville James Cook大學的教授說。
His research group has conducted experiments which involved building cages to keep fish away from sections of reef.
他的研究團隊進行了幾個實驗，就是將幾段珊瑚礁以網籠隔開阻絕魚群的進入。
They found that three times as much new coral developed in areas where the fish were present as in the caged portions.
他們發現魚群環繞的珊瑚，其生長率比被網籠隔離的珊瑚足足高出三倍之多。
Parrotfish in particular use their serrated jaws to scrape off incipient algae and plants.
特別是鸚哥魚，牠們可以用有鋸齒狀的下顎將新生的海藻及植物整個刮除。
More recently, his team has also identified the rabbit fish - a brown, bland-looking species - as a potentially important harvester of seaweed.
另外，最近他的團隊也確認到褐籃子魚(臭肚) – 這種褐色、看起來性情溫和的魚類 – 是強而有力重要的海草收割機。
"So managing fisheries can help to maintain the reef's resilience to future climate change," he said.
"因此管理漁業能有助於維持珊瑚礁在面對未來氣候變遷保有彈性及恢復力，"他說。
In recent years, Marine Protected Areas have been set up along the Great Barrier Reef in order to provide sanctuaries where fish and other marine creatures can grow and develop.
近年來，大堡礁的四周已設置了好幾個海洋保護區，為的就是提供魚類及其它的海洋生物一個得以生長及發展的環境。
Dr Peter Doherty from the Australian Institute of Marine Science presented data showing that just two years of protection brought significant increases in populations of important species such as coral trout and tropical snapper.
來自澳洲海洋科學學會的Peter Doherty博士提出的資料顯示，僅僅兩年的保育使得重要的魚類，如花斑刺鰓鮨及熱帶真鯛，在數量上都有顯著的成長。
"More importantly, more eggs are being produced... nearly three times the number of eggs per unit area being produced in the surrounding territory," he said.
"更重要地，產卵的數量也提高了....在周邊的範圍內每一區的產卵量都高出了三倍之多，"他說。
The eggs, he showed, travelled well outside the boundaries of the protected zones, potentially increasing fish populations in non-protected areas too.
他告訴大家，這些卵隨波漂流到保護區邊界以外，連帶也可能增加非保護區魚群的數量。
Burning issue
The scientists emphasised that a comprehensive approach to reef protection would include measures to lower greenhouse gas emissions and to reduce run-off from agricultural land and human settlements along the coast.
科學家強調綜觀珊瑚礁保育的方法包含了降低溫室效應的氣體排放量、減少耕地及沿海住家的排水量。
"You have got a three- to nine-fold increase in sediment loss," said Professor Iain Gordon from the governmental research organisation CSIRO.
"沉積物招致的損害已經由原來的三倍增加到九倍之多，"來自CSIRO政府研究組織的Iain Gordon教授說。
"[There are] increases in nutrients that feed into the system, nitrates and phosphates and also new kinds of chemicals in the water that is around the reef; pesticides and herbicides, they haven't been there before."
"增加的養份進到生態系統裡，硝酸鹽、磷酸鹽，還有其它幾種化學藥品滲入珊瑚礁附近的水域；殺蟲劑和除草劑，這些是從前不曾有過的。"
Professor Ove Hoegh-Guldberg from the University of Queensland noted that unusually warm water in 1998 and 2002 had bleached and damaged coral in southern parts of the Barrier Reef.
來自Queensland大學的Ove Hoegh-Guldberg教授注意到1998年及2000年異常溫暖的海水使得大堡礁南部的珊瑚白化與損害。
"The reef literally goes from being brown and healthy to being a stark white, and this happens with very small changes in temperature," he said.
"在極些微的溫度變化下，原本棕色和健康的珊瑚真的完全變白，"他說。
In the past, he said, bleaching events happened only at the warm extremes of natural cycles such as El Nino; but now the overall water temperature is higher, which makes the peaks of the cycles more harmful to coral.
他表示，在過去，珊瑚白化事件都只發生在大自然週期最溫暖的時候，像是聖嬰現象；而現在則是水溫全面的升高，這使得週期當中的高峰期對珊瑚的危害更嚴重。
"Because sea temperatures are now a lot higher, they are now reaching the thresholds at which coral get into distress, and of course it is really large scale impacts."
"由於現在海水的溫度高出許多，已經到達一個對珊瑚造成威脅的門檻，當然這是極大程度的衝擊。"
At high temperatures, coral polyps expel the algae which normally live with them in a symbiotic relationship, turning the reef white. The algae typically provide most of the polyp's nutrition; without them, the polyps eventually die.
高溫下，珊瑚蟲會驅走這些正常情況下享有共生的關係的海藻，轉而使得珊瑚變白。海藻很典型地供應珊瑚蟲大部份的養份；沒有了海藻，珊瑚蟲終究會死亡。
Even if a bleached zone contains live polyps and carries the potential to recover when waters cool, a quick invasion of kelp, or types of algae that do not live symbiotically with coral, can make the die-off permanent - hence the protective role of plant-munchng fish.
即使白化區仍有活著的珊瑚蟲，當水溫降了下來時還是有復原的機會，而巨藻或其它幾類無法與珊瑚共生的海藻的快速入侵下，致使珊瑚相繼死絕 - 由此可知這些大啖植物的魚類，牠們的保護作用。
The Great Barrier Reef is worth about six billion Australian dollars (US$5.5bn; £2.8bn) to the national economy, primarily through tourism and fishing.
大堡礁對國家經濟價值約六十億澳幣，主要是由於觀光與漁業收入。
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/7306693.stm
Published: 2008/03/20 14:31:31 GMT
© BBC MMVIII
A healthy fish population could be the key to ensuring coral reefs survive the impacts of climate change, pollution, overfishing and other threats.
健康合理的魚群數量可能是確保珊瑚礁在氣候變遷、環境污染、過度捕撈及其他威脅等各種衝擊下存活的關鍵因素。
Australian scientists found that some fish act as "lawnmowers", keeping coral free of kelp and unwanted algae.
澳洲的科學家們發現一些魚類著實扮演了"除草機"的角色，使珊瑚礁得以避開巨藻以及多餘海藻的糾纏。
At a briefing to parliamentarians in Canberra, they said protected areas were rebuilding fish populations in some parts of the Great Barrier Reef.
在對坎培拉國會議員做的簡報中他們表示，在部份大堡礁的保護區域中已重建魚群數量。
Warming seas are likely to affect the reef severely within a few decades.
最可能在短短幾十年間嚴重地影響珊瑚礁的就是海洋的暖化。
Pollution is also a growing problem, particularly fertilisers that wash from agricultural land into water around the reef, stimulating the growth of plants that stifle the coral.
環境污染也是一個日益嚴重的問題，特別是由耕地上所使用的肥料被沖刷到珊瑚礁附近的水域後，刺激植物的生長進而使珊瑚窒息。
Protect and survive
The assembled experts told parliamentarians that fish able to graze on invading plants played a vital role in the health of reef ecosystems.
前來參加會議的專家告訴國會議員，能夠吃掉大批入侵植物的魚群，對珊瑚礁生態系統的健康狀態扮演了不可或缺的角色。
"The Great Barrier Reef is still a resilient system... and herbivorous fish play a critical role in that regenerative capacity, by keeping the dead coral space free of algae, so that new juvenile coral can re-establish themselves," said Professor Terry Hughes from James Cook University in Townsville.
"大堡礁仍舊是一個具有彈性及恢復力的系統，這些草食性的魚類對再生能力起了關鍵性的作用，牠們使海藻無法佔據在已死去的珊瑚上，因此新生的珊瑚可以在上頭生長，" Terry Hughes這位來自Townsville James Cook大學的教授說。
His research group has conducted experiments which involved building cages to keep fish away from sections of reef.
他的研究團隊進行了幾個實驗，就是將幾段珊瑚礁以網籠隔開阻絕魚群的進入。
They found that three times as much new coral developed in areas where the fish were present as in the caged portions.
他們發現魚群環繞的珊瑚，其生長率比被網籠隔離的珊瑚足足高出三倍之多。
Parrotfish in particular use their serrated jaws to scrape off incipient algae and plants.
特別是鸚哥魚，牠們可以用有鋸齒狀的下顎將新生的海藻及植物整個刮除。
More recently, his team has also identified the rabbit fish - a brown, bland-looking species - as a potentially important harvester of seaweed.
另外，最近他的團隊也確認到褐籃子魚(臭肚) – 這種褐色、看起來性情溫和的魚類 – 是強而有力重要的海草收割機。
"So managing fisheries can help to maintain the reef's resilience to future climate change," he said.
"因此管理漁業能有助於維持珊瑚礁在面對未來氣候變遷保有彈性及恢復力，"他說。
In recent years, Marine Protected Areas have been set up along the Great Barrier Reef in order to provide sanctuaries where fish and other marine creatures can grow and develop.
近年來，大堡礁的四周已設置了好幾個海洋保護區，為的就是提供魚類及其它的海洋生物一個得以生長及發展的環境。
Dr Peter Doherty from the Australian Institute of Marine Science presented data showing that just two years of protection brought significant increases in populations of important species such as coral trout and tropical snapper.
來自澳洲海洋科學學會的Peter Doherty博士提出的資料顯示，僅僅兩年的保育使得重要的魚類，如花斑刺鰓鮨及熱帶真鯛，在數量上都有顯著的成長。
"More importantly, more eggs are being produced... nearly three times the number of eggs per unit area being produced in the surrounding territory," he said.
"更重要地，產卵的數量也提高了....在周邊的範圍內每一區的產卵量都高出了三倍之多，"他說。
The eggs, he showed, travelled well outside the boundaries of the protected zones, potentially increasing fish populations in non-protected areas too.
他告訴大家，這些卵隨波漂流到保護區邊界以外，連帶也可能增加非保護區魚群的數量。
Burning issue
The scientists emphasised that a comprehensive approach to reef protection would include measures to lower greenhouse gas emissions and to reduce run-off from agricultural land and human settlements along the coast.
科學家強調綜觀珊瑚礁保育的方法包含了降低溫室效應的氣體排放量、減少耕地及沿海住家的排水量。
"You have got a three- to nine-fold increase in sediment loss," said Professor Iain Gordon from the governmental research organisation CSIRO.
"沉積物招致的損害已經由原來的三倍增加到九倍之多，"來自CSIRO政府研究組織的Iain Gordon教授說。
"[There are] increases in nutrients that feed into the system, nitrates and phosphates and also new kinds of chemicals in the water that is around the reef; pesticides and herbicides, they haven't been there before."
"增加的養份進到生態系統裡，硝酸鹽、磷酸鹽，還有其它幾種化學藥品滲入珊瑚礁附近的水域；殺蟲劑和除草劑，這些是從前不曾有過的。"
Professor Ove Hoegh-Guldberg from the University of Queensland noted that unusually warm water in 1998 and 2002 had bleached and damaged coral in southern parts of the Barrier Reef.
來自Queensland大學的Ove Hoegh-Guldberg教授注意到1998年及2000年異常溫暖的海水使得大堡礁南部的珊瑚白化與損害。
"The reef literally goes from being brown and healthy to being a stark white, and this happens with very small changes in temperature," he said.
"在極些微的溫度變化下，原本棕色和健康的珊瑚真的完全變白，"他說。
In the past, he said, bleaching events happened only at the warm extremes of natural cycles such as El Nino; but now the overall water temperature is higher, which makes the peaks of the cycles more harmful to coral.
他表示，在過去，珊瑚白化事件都只發生在大自然週期最溫暖的時候，像是聖嬰現象；而現在則是水溫全面的升高，這使得週期當中的高峰期對珊瑚的危害更嚴重。
"Because sea temperatures are now a lot higher, they are now reaching the thresholds at which coral get into distress, and of course it is really large scale impacts."
"由於現在海水的溫度高出許多，已經到達一個對珊瑚造成威脅的門檻，當然這是極大程度的衝擊。"
At high temperatures, coral polyps expel the algae which normally live with them in a symbiotic relationship, turning the reef white. The algae typically provide most of the polyp's nutrition; without them, the polyps eventually die.
高溫下，珊瑚蟲會驅走這些正常情況下享有共生的關係的海藻，轉而使得珊瑚變白。海藻很典型地供應珊瑚蟲大部份的養份；沒有了海藻，珊瑚蟲終究會死亡。
Even if a bleached zone contains live polyps and carries the potential to recover when waters cool, a quick invasion of kelp, or types of algae that do not live symbiotically with coral, can make the die-off permanent - hence the protective role of plant-munchng fish.
即使白化區仍有活著的珊瑚蟲，當水溫降了下來時還是有復原的機會，而巨藻或其它幾類無法與珊瑚共生的海藻的快速入侵下，致使珊瑚相繼死絕 - 由此可知這些大啖植物的魚類，牠們的保護作用。
The Great Barrier Reef is worth about six billion Australian dollars (US$5.5bn; £2.8bn) to the national economy, primarily through tourism and fishing.
大堡礁對國家經濟價值約六十億澳幣，主要是由於觀光與漁業收入。
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/7306693.stm
Published: 2008/03/20 14:31:31 GMT
© BBC MMVIII
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