Sea snails show impact of more acidic ocean 海螺顯示海洋酸化的影響

Sat, Dec 15, 2012 - Page 10

The shells of some marine snails in the seas around Antarctica are dissolving as the water becomes more acidic, threatening the food chain, a study published in the journal Nature Geoscience said.

Oceans soak up about a quarter of the carbon dioxide released into the atmosphere each year and as CO2 levels in the atmosphere increase from burning fossil fuels, so do ocean levels, making seas more acidic.

Ocean acidification is one of the effects of climate change and threatens coral reefs, marine ecosystems and wildlife.

The shell of the pteropod sea snail in the Southern Ocean was severely dissolved by more acidic surface water, the researchers from the British Antarctic Survey, Royal Netherlands Institute for Sea Research, the US National Oceanic and Atmospheric Administration (NOAA) and other institutions found.

And although the snails did not necessarily die, it increased their vulnerability to predators and infection which could affect other parts of the food chain.

The sea snails are an important source of food for fish and birds as well as an indicator of marine ecosystem health.

Since the start of the industrial revolution, the acidity of surface ocean waters has increased by 30 percent, according to NOAA research.

If CO2 levels continue to rise in the future, surface waters could be almost 150 percent more acidic by the end of this century, levels which have not been experienced for more than 20 million years.

(Reuters)

南極周邊海洋的一些海螺螺殼,因海水變得較酸而消溶,該現象將威脅食物鏈,一份刊載於《自然地球科學》期刊的研究指出。

海洋每年吸收約四分之一釋放進大氣的二氧化碳,而當大氣中的二氧化碳濃度因燃燒化石燃料而增加時,海洋的CO2濃度也增加,而使海洋更酸。

海洋酸化是氣候變遷的效應之一,並威脅珊瑚礁、海洋生態系與野生動物。

英國南極調查所、荷蘭皇家海洋研究所、美國國家海洋暨大氣總署(NOAA)以及其他研究機構的研究人員發現,南冰洋的翼足類海螺被更酸的表層水嚴重溶解。

雖然海螺不必然死亡,但增加被掠食與感染的脆弱性,恐影響其他部分的食物鏈。

海螺是魚類及鳥類的重要食物來源,同時是海洋生態系健康狀況的一項指標。

自工業革命開始以來,海洋表層水的酸度已增加百分之三十,根據NOAA研究。

如果未來CO2濃度繼續上升,到本世紀結束時,表層水恐較酸達近百分之一百五十,這是逾兩千萬年未曾經歷過的情形。

(路透/翻譯:魏國金)