據(jù)近期《自然—地球科學(xué)》上的一項研究顯示,，南大洋軟體動物的外殼正呈現(xiàn)出嚴(yán)重溶解的跡象。這表明海洋酸化對海洋生態(tài)系統(tǒng)的影響正在顯現(xiàn),。
Geraint Tarling等人對環(huán)繞南極洲的南大洋表層水域中活軟體動物的外殼進行檢查,，發(fā)現(xiàn)從海洋酸性程度較大區(qū)域獲取的外殼樣本顯著表現(xiàn)出了溶解的征兆。他們認(rèn)為這種溶解產(chǎn)生的原因是二氧化碳富集的深層水與受大氣中二氧化碳影響的表層水的共同作用,。
Justin Ries在一篇評論文章中稱該酸腐蝕記錄“或許揭示著南大洋大部分區(qū)域中表層水所儲藏著的物質(zhì)”,。(生物谷Bioon.com)
DOI:10.1038/ngeo1635
PMC:
PMID:
Extensive dissolution of live pteropods in the Southern Ocean
N. Bednaršek,1, 2, 3 G. A. Tarling,1 D. C. E. Bakker,2 S. Fielding,1 E. M. Jones,4 H. J. Venables,1 P. Ward,1 A. Kuzirian,5 B. Lézé,2 R. A. Feely6 & E. J. Murphy1
The carbonate chemistry of the surface ocean is rapidly changing with ocean acidification, a result of human activities1. In the upper layers of the Southern Ocean, aragonite—a metastable form of calcium carbonate with rapid dissolution kinetics—may become undersaturated by 2050 (ref. 2). Aragonite undersaturation is likely to affect aragonite-shelled organisms, which can dominate surface water communities in polar regions3. Here we present analyses of specimens of the pteropod Limacina helicina antarctica that were extracted live from the Southern Ocean early in 2008. We sampled from the top 200 m of the water column, where aragonite saturation levels were around 1, as upwelled deep water is mixed with surface water containing anthropogenic CO2. Comparing the shell structure with samples from aragonite-supersaturated regions elsewhere under a scanning electron microscope, we found severe levels of shell dissolution in the undersaturated region alone. According to laboratory incubations of intact samples with a range of aragonite saturation levels, eight days of incubation in aragonite saturation levels of 0.94–1.12 produces equivalent levels of dissolution. As deep-water upwelling and CO2 absorption by surface waters is likely to increase as a result of human activities2, 4, we conclude that upper ocean regions where aragonite-shelled organisms are affected by dissolution are likely to expand.
