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The role of trace metals in controlling structure and function of microbial communities in contemporary oceans
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Effects of aluminum on the ocean carbon cycle and climate change: the Iron-Aluminum Hypothesis P-C3-07 Linbin Zhou* , South China Sea Institute of Oceanology,
Chinese Academy of Sciences, Guangzhou, China Yehui Tan, South China Sea Institute of Oceanology,
Chinese Academy of Sciences, Guangzhou, China Liangmin Huang, South China Sea Institute of Oceanology,
Chinese Academy of Sciences, Guangzhou, China Claude Fortin, Institut national de la recherche scientifique, Centre Eau
Terre Environnement, Quebec, Canada Peter G.C. Campbell, Institut national de la recherche scientifique, Centre Eau
Terre Environnement, Quebec, Canada Presenter Email: zhoulb@scsio.ac.cn/zhoulinbin2004@163.com |
In contrast to substantial studies and established knowledge of aluminum (Al) effects (mainly toxicity) on freshwater organisms and terrestrial plants, and even on human health, only a few studies of Al effects on marine organisms have been reported, and our understanding of the role of Al in marine biogeochemistry is limited. Here we will present our understanding of the effects of Al on marine organisms, especially the beneficial effects of Al on marine phytoplankton growth, and we discuss possible links of Al to the biological pump and the global carbon cycle. We propose a revised Iron (Fe) Hypothesis, i.e., the Fe–Al Hypothesis that introduces the idea that Al as well as Fe play an important role in the glacial-interglacial change in atmospheric CO2 concentrations and climate change. We propose that Al could not only facilitate Fe utilization, dissolved organic phosphorus utilization and nitrogen fixation by marine phytoplankton, enhancing phytoplankton biomass and carbon fixation in the upper oceans, but also reduce the decomposition and decay of biogenic matter. As a result, Al allows potentially more carbon to be exported and sequestered in the ocean depths through the biological pump. We also propose that Al binds to superoxide to form an Al-superoxide complex, which could catalyze the reduction of Fe(III) to Fe(II) and thus facilitate Fe utilization by marine phytoplankton and other microbes. Further ocean fertilization experiments with Fe and Al are suggested, to clarify the role of Al in the stimulation of phytoplankton growth and carbon sequestration in the ocean depths. |
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