一项研究说，到本世纪末，CO2的增加可能导致幼鱼被捕食者攻击。在海水中，CO2溶解并产生一种弱酸，而科学家预计，在大气CO2浓度高于目前将近百万分之390（ppm）的时候，海洋表面水将变得更酸。Philip Munday及其同事检查了如果CO2浓度继续以当前的速率增加，那么本世纪可能发生的海洋酸性增加对幼鱼的影响。这组科学家把小丑鱼和雀鲷幼鱼放在CO2浓度为700ppm和850ppm的海水中，然后观察了这些鱼对于捕食者气味的反应。
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这些作者说，最初避开这种气味的鱼的半数在700ppm和850ppm的海水中生活4天之后探测到这种气味的能力更少，所有这些幼鱼看上去都变得被这种气味所吸引。当曾经接触到升高的CO2浓度的幼鱼转移到自然珊瑚礁栖息地中的时候，这些鱼在捕食者周围用了更多的时间，而且被吃掉的比率是对照组的5到9倍。这组作者说，这项研究提示，海洋酸化可能通过导致新孵化出的幼鱼对周围的捕食者更不警觉从而减少鱼类的种群。(生物谷Bioon.net)
生物谷推荐原文出处：
PNAS doi: 10.1073/pnas.1004519107
Replenishment of fish populations is threatened by ocean acidification
Philip L. Mundaya,1, Danielle L. Dixsona, Mark I. McCormicka, Mark Meekanb, Maud C. O. Ferraric, and Douglas P. Chiversd
aAustralian Research Council Centre of Excellence for Coral Reef Studies and School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia;
b Australian Institute of Marine Science, Perth, Western Australia 6009, Australia;
cDepartment of Environmental Science and Policy, University of California, Davis, CA 95616; and
dDepartment of Biology, University of Saskatchewan, SK, Canada S7N 5E2
There is increasing concern that ocean acidification, caused by the uptake of additional CO2 at the ocean surface, could affect the functioning of marine ecosystems; however, the mechanisms by which population declines will occur have not been identified, especially for noncalcifying species such as fishes. Here, we use a combination of laboratory and field-based experiments to show that levels of dissolved CO2 predicted to occur in the ocean this century alter the behavior of larval fish and dramatically decrease their survival during recruitment to adult populations. Altered behavior of larvae was detected at 700 ppm CO2, with many individuals becoming attracted to the smell of predators. At 850 ppm CO2, the ability to sense predators was completely impaired. Larvae exposed to elevated CO2 were more active and exhibited riskier behavior in natural coral-reef habitat. As a result, they had 5–9 times higher mortality from predation than current-day controls, with mortality increasing with CO2 concentration. Our results show that additional CO2 absorbed into the ocean will reduce recruitment success and have far-reaching consequences for the sustainability of fish populations.
