Ocean acidification rapidly reduces dinitrogen fixation associated with the hermatypic coral Seriatopora hystrix
Ocean acidification rapidly reduces dinitrogen fixation associated with the hermatypic coral Seriatopora hystrix
复制标题
DOI：
10.3354/meps10912
复制
发表时间：
2014-09
影响因子：
2.5
通讯作者：
Nils Rädecker;Friedrich W. Meyer;V. Bednarz;U. Cardini;C. Wild
中科院分区：
文献类型：
--
作者：
Nils Rädecker;Friedrich W. Meyer;V. Bednarz;U. Cardini;C. Wild
由于珊瑚相关鞭毛藻的生产力和生长受到氮 (N) 的限制，因此珊瑚相关微生物对二氮 (N2) 的固定可能对于维持珊瑚鞭毛藻共生至关重要。因此，了解未来气候变化对珊瑚全生物固氮的影响至关重要。这项实验室研究首次使用乙炔还原测定结合钙化测量来研究海洋酸化对与热带造血型珊瑚 Seriatopora hystrix 相关的 N2 固定活性的短期影响。研究结果表明，与当前情景（p CO2 486 µatm）相比，模拟海洋酸化（p CO2 1080 µatm）导致与 S. hystrix 相关的 N2 固定率快速显着下降（53%）。此外，与珊瑚全生物相关的 N2 固定与其钙化率呈正指数关系。这表明，在高二氧化碳条件下，造血型珊瑚的钙化率即使小幅下降也可能导致氮固定活动减少，因为这两个过程可能会在珊瑚全生物体中争夺能量。最终，氮限制的加剧加上骨骼生长的下降可能会引发珊瑚生产力的负反馈循环，从而加剧海洋酸化的负面长期影响。
Since productivity and growth of coral-associated dinoflagellate algae is nitrogen (N)-limited, dinitrogen (N2) fixation by coral-associated microbes is likely crucial for maintaining the coraldinoflagellate symbiosis. It is thus essential to understand the effects future climate change will have on N2 fixation by the coral holobiont. This laboratory study is the first to investi- gate short-term effects of ocean acidification on N2 fixation activity associated with the tropical, hermatypic coral Seriatopora hystrix using the acetylene reduction assay in combination with cal- cification measurements. Findings reveal that simulated ocean acidification (p CO2 1080 µatm) caused a rapid and significant decrease (53%) in N2 fixation rates associated with S. hystrix com- pared to the present day scenario (p CO2 486 µatm). In addition, N2 fixation associated with the coral holobiont showed a positive exponential relationship with its calcification rates. This sug- gests that even small declines in calcification rates of hermatypic corals under high CO2 conditions may result in decreased N2 fixation activity, since these 2 processes may compete for energy in the coral holobiont. Ultimately, an intensified N limitation in combination with a decline in skeletal growth may trigger a negative feedback loop on coral productivity exacerbating the negative long-term effects of ocean acidification.