氣候變化促使全球海洋物種遠(yuǎn)離赤道

A University of Auckland-led research showed for the first time at a global scale and across all kinds of species that marine life has been changing its distribution away from the equator in direct response to climate change.

奧克蘭大學(xué)領(lǐng)導(dǎo)的一項(xiàng)研究首次表明，在全球范圍內(nèi)，所有種類的海洋生物都在改變它們的分布，遠(yuǎn)離赤道，這是對(duì)氣候變化的直接反應(yīng)。

As predicted by climate warming, the number of species has decreased at the equator and increased in the sub-tropics since the 1950s.

正如氣候變暖所預(yù)測的那樣，自20世紀(jì)50年代以來，赤道物種數(shù)量減少，亞熱帶物種數(shù)量增加。

This was the case across all 48,661 species, and when they were split into those living on the seabed (benthic) and in open water (pelagic), fish, mollusks and crustaceans.

所有48661個(gè)物種都是如此，當(dāng)它們被分為生活在海底(底棲)和開放水域(遠(yuǎn)洋)的魚類、軟體動(dòng)物和甲殼類動(dòng)物時(shí)。

[Photo/CFP]

The new study showed that pelagic species had shifted poleward in the northern hemisphere more than benthic. The lack of a similar shift in the southern hemisphere was because ocean warming has been greater in the northern than southern hemisphere.

這項(xiàng)新研究表明，在北半球，遠(yuǎn)洋物種向極地遷移的時(shí)間多于底棲物種。南半球之所以沒有出現(xiàn)類似的變化，是因?yàn)楸卑肭虻暮Ｑ笞兣潭却笥谀习肭颉?/p>

Previously, the tropics were considered stable and an ideal temperature for life because so many species occur there. Now, people realize that the tropics are not so stable and are increasingly too hot for many species.

以前，熱帶地區(qū)被認(rèn)為是穩(wěn)定的，是適合生命生存的理想溫度，因?yàn)槟抢镉泻芏辔锓N?，F(xiàn)在，人們意識(shí)到熱帶地區(qū)不是那么穩(wěn)定，而且對(duì)許多物種來說越來越熱。

The study was the culmination of lead author Chhaya Chaudhary's PhD at the University of Auckland and was built on a range of studies in a research group that studied the data on particular taxonomic groups in detail, including crustaceans, fish and worms.

該研究是第一作者Chhaya Chaudhary在奧克蘭大學(xué)的博士學(xué)位的成果，建立在一個(gè)研究小組的一系列研究之上，該研究小組詳細(xì)研究了特定分類群的數(shù)據(jù)，包括甲殼類動(dòng)物、魚類和蠕蟲。

The data were obtained from the Ocean Biodiversity Information System (OBIS), a freely accessible online world database whose establishment was led by the university's Professor Mark Costello as part of the Census of Marine Life, a global marine discovery program from 2000 to 2010. The records of when and where species were reported were summed into latitudinal bands and a statistical model was used to account for variation in sampling.

這些數(shù)據(jù)來自海洋生物多樣性信息系統(tǒng)(OBIS)，這是一個(gè)免費(fèi)獲取的在線世界數(shù)據(jù)庫，由該大學(xué)的馬克·科斯特洛教授領(lǐng)導(dǎo)建立，是2000年至2010年全球海洋發(fā)現(xiàn)項(xiàng)目“海洋生物普查”的一部分。報(bào)告物種的時(shí)間和地點(diǎn)的記錄被歸納為緯度帶，并使用一種統(tǒng)計(jì)模型來解釋取樣的變化。

Last year, Professor Costello co-authored a study showing that while marine biodiversity peaked at the equator during the last ice age, 20,000 years ago, it had already flattened before industrial global warming. That study used fossil records of marine plankton buried in deep sea sediments to track the change in diversity over thousands of years.

去年，科斯特洛教授與人合著的一項(xiàng)研究表明，盡管海洋生物多樣性在2萬年前的上一個(gè)冰河時(shí)期達(dá)到了頂峰，但在工業(yè)全球變暖之前，它就已經(jīng)變平了。該研究利用埋藏在深海沉積物中的海洋浮游生物化石記錄，來追蹤數(shù)千年來海洋浮游生物多樣性的變化。

This latest study on a decadal timescale shows this flattening has continued in the past century, and the number of species now dips at the equator. The study, and others in progress, show that the number of marine species declines once the annual mean sea temperature is above 20 to 25 degrees Celsius (varying with different kinds of species).

這項(xiàng)以10年為尺度的最新研究表明，這一平緩趨勢在過去的一個(gè)世紀(jì)里一直在繼續(xù)，赤道地區(qū)的物種數(shù)量現(xiàn)在正在下降。這項(xiàng)研究以及其他正在進(jìn)行的研究表明，一旦年平均海水溫度超過20至25攝氏度，海洋物種的數(shù)量就會(huì)下降(因物種的不同而不同)。

As one of the Lead Authors on the current 6th Assessment Report of the International Panel on Climate Change (IPCC), Professor Costello said the findings are significant.

作為國際氣候變化專門委員會(huì)(IPCC)第六次評(píng)估報(bào)告的主要作者之一，科斯特洛教授表示，這些發(fā)現(xiàn)意義重大。

"Our work shows that human-caused climate change has already affected marine biodiversity at a global scale across all kinds of species. Climate change is with us now, and its pace is accelerating.

“我們的工作表明，人類造成的氣候變化已經(jīng)在全球范圍內(nèi)影響了各種物種的海洋生物多樣性。氣候變化現(xiàn)在就在我們身邊，而且速度還在加快。

"We can predict the general shift in species diversity, but because of the complexity of ecological interactions, it is unclear how species' abundance and fisheries will change with climate change."

“我們可以預(yù)測物種多樣性的總體變化，但由于生態(tài)相互作用的復(fù)雜性，目前還不清楚物種的豐富度和漁業(yè)將如何隨著氣候變化而變化。”