Diatoms Dominate and Alter Marine Food-Webs When CO2 Rises
Diatoms Dominate and Alter Marine Food-Webs When CO2 Rises
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DOI：
10.3390/d11120242
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发表时间：
2019-12
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影响因子：
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通讯作者：
Ben P. Harvey;S. Agostini;K. Kon;S. Wada;J. Hall‐Spencer
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文献类型：
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作者：
Ben P. Harvey;S. Agostini;K. Kon;S. Wada;J. Hall‐Spencer
硅藻在海洋食物网中非常重要，任何人类引起的硅藻丰度变化都可能对海洋生态产生重大影响。随着北太平洋天然海水二氧化碳梯度的 pCO2 增加，大型链形成硅藻 Biddulphia biddulphiana 的丰度大大增加。在pCO2参考水平的地区，很难找到它，但随着海水二氧化碳水平的上升，它取代了海藻，成为海底主要的栖息地形成物种。这种硅藻藻土支持着一个海洋无脊椎动物群落，该群落的多样性要低得多，并且与当今 pCO2 水平下发现的底栖群落完全不同。海水中二氧化碳的富集刺激了底栖硅藻的生长和光合效率，但减少了腹足动物和海胆等钙化食草动物的丰度。这些观察结果表明，海洋酸化将改变光带群落组成，从而使沿海食物网结构和生态系统功能均质化、简化，并更强烈地受到季节性藻华的影响。
Diatoms are so important in ocean food-webs that any human induced changes in their abundance could have major effects on the ecology of our seas. The large chain-forming diatom Biddulphia biddulphiana greatly increases in abundance as pCO2 increases along natural seawater CO2 gradients in the north Pacific Ocean. In areas with reference levels of pCO2, it was hard to find, but as seawater carbon dioxide levels rose, it replaced seaweeds and became the main habitat-forming species on the seabed. This diatom algal turf supported a marine invertebrate community that was much less diverse and completely differed from the benthic communities found at present-day levels of pCO2. Seawater CO2 enrichment stimulated the growth and photosynthetic efficiency of benthic diatoms, but reduced the abundance of calcified grazers such as gastropods and sea urchins. These observations suggest that ocean acidification will shift photic zone community composition so that coastal food-web structure and ecosystem function are homogenised, simplified, and more strongly affected by seasonal algal blooms.