全世界海洋中的高濃度二氧化碳抑制了正常的珊瑚生長,，這提示隨著大氣中的碳越來越多地溶解到水中，珊瑚礁面臨著艱難的時刻,。Derek Manzello及其同事研究了在巴拿馬和加拉帕戈斯群島的呈天然酸性,、高二氧化碳海水中的珊瑚礁結構,。這組科學家發(fā)現(xiàn),，與來自海洋二氧化碳濃度更低的巴哈馬的珊瑚礁相比，這些地方的珊瑚礁的結構粘合劑幾乎不存在,。相關論文發(fā)表在美國《國家科學院院刊》（PNAS）上,。
此前的研究已經表明自從產業(yè)革命以來釋放到大氣層中的碳的大約1/3已經以二氧化碳的形式溶解到了海洋中，這讓海洋酸性更強,，而且改變了海洋生物的化學結構單元的基本平衡,，例如利用碳組裝其礦物質骨骼的珊瑚等海洋生物。這組作者證明了在熱帶東太平洋的富含二氧化碳的水中生長的珊瑚產生的礦物粘合劑很少,，常常只能填充珊瑚骨骼中百分之幾的小孔,，而來自巴哈馬的樣本中的小孔幾乎全部被填充了。由于粘合不良的珊瑚礁容易遭到自然侵蝕,，這項研究中的珊瑚礁讓人們得以一窺生活在高二氧化碳世界中的珊瑚的未來,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS，doi: 10.1073/pnas.0712167105,，Derek P. Manzello,，Chris Langdon
Poorly cemented coral reefs of the eastern tropical Pacific: Possible insights into reef development in a high-CO2 world
Derek P. Manzello*,†,‡, Joan A. Kleypas§, David A. Budd¶, C. Mark Eakin‖, Peter W. Glynn†, and Chris Langdon†
+Author Affiliations
*Cooperative Institute of Marine and Atmospheric Studies,
†Rosenstiel School, Marine Biology and Fisheries, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149;
§Institute for the Study of Society and Environment, National Center for Atmospheric Research, Boulder, CO 80307;
¶Department of Geological Sciences, University of Colorado, Boulder, CO 80309; and
‖National Oceanic and Atmospheric Administration, Silver Spring, MD 20910
Edited by David M. Karl, University of Hawaii, Honolulu, HI, and approved May 16, 2008 (received for review December 22, 2007)
Abstract
Ocean acidification describes the progressive, global reduction in seawater pH that is currently underway because of the accelerating oceanic uptake of atmospheric CO2. Acidification is expected to reduce coral reef calcification and increase reef dissolution. Inorganic cementation in reefs describes the precipitation of CaCO3 that acts to bind framework components and occlude porosity. Little is known about the effects of ocean acidification on reef cementation and whether changes in cementation rates will affect reef resistance to erosion. Coral reefs of the eastern tropical Pacific (ETP) are poorly developed and subject to rapid bioerosion. Upwelling processes mix cool, subthermocline waters with elevated pCO2 (the partial pressure of CO2) and nutrients into the surface layers throughout the ETP. Concerns about ocean acidification have led to the suggestion that this region of naturally low pH waters may serve as a model of coral reef development in a high-CO2 world. We analyzed seawater chemistry and reef framework samples from multiple reef sites in the ETP and found that a low carbonate saturation state (Ω) and trace abundances of cement are characteristic of these reefs. These low cement abundances may be a factor in the high bioerosion rates previously reported for ETP reefs, although elevated nutrients in upwelled waters may also be limiting cementation and/or stimulating bioerosion. ETP reefs represent a real-world example of coral reef growth in low-Ω waters that provide insights into how the biological–geological interface of coral reef ecosystems will change in a high-CO2 world.
