Effects of depth-cycling on nutrient uptake and biomass production in the giant kelp Macrocystis pyrifera
Effects of depth-cycling on nutrient uptake and biomass production in the giant kelp Macrocystis pyrifera
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DOI：
10.1016/j.rser.2021.110747
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发表时间：
2021-05
影响因子：
15.9
通讯作者：
Ignacio A. Navarrete;Diane Y. Kim;Cindy Wilcox;D. Reed;D. Ginsburg;J. Dutton;J. Heidelberg;Yubin Raut;Brian Wilcox
中科院分区：
文献类型：
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作者：
Ignacio A. Navarrete;Diane Y. Kim;Cindy Wilcox;D. Reed;D. Ginsburg;J. Dutton;J. Heidelberg;Yubin Raut;Brian Wilcox
透光区的季节性或长期营养限制限制了世界大部分海洋中海藻（大型藻类）的大规模种植，阻碍了大型藻类作为生物燃料原料的发展。一种可能的解决方案是使用昼夜深度循环方法提供营养，在夜间将大型藻类在营养丰富的深水和白天透光区内的浅水之间移动。这项研究测试了深度循环对巨藻巨藻（可再生生物质生产的目标物种）的生长、形态和化学成分的影响。在深度循环条件下生长的巨型海带的平均生长率为每天 5%，产生的生物量（湿重）是在没有深度循环的海带床上生长的个体的四倍。对深度循环海带组织的分析显示，蛋白质水平升高、C:N 比率较低，以及不同的 δ15N 和 δ13C 值，表明深度循环海带不缺氮，并且吸收了深水中的营养物质。深度循环的海带还表现出更小、更厚壁的气囊和更大的叶片。总的来说，这项研究支持进一步研究深度循环作为大型藻类养殖策略。
Seasonal or chronic nutrient limitations in the photic zone limit large-scale cultivation of seaweed (macroalgae) in much of the world's oceans, hindering the development of macroalgae as a biofuel feedstock. One possible solution is to supply nutrients using a diel depth-cycling approach, physically moving the macroalgae between deep nutrient-rich water at night and shallow depths within the photic zone during the day. This study tested the effects of depth-cycling on the growth, morphology, and chemical composition of the giant kelpMacrocystis pyrifera, a target species for renewable biomass production. Giant kelp grown under depth-cycling conditions had an average growth rate of 5% per day and produced four times more biomass (wet weight) than individuals grown in a kelp bed without depth-cycling. Analysis of tissue from the depth-cycled kelp showed elevated levels of protein, lower C:N ratios, and distinct δ15N and δ13C values suggesting that the depth-cycled kelp were not nitrogen-deficient and assimilated nutrients from deep water. Depth-cycled kelp also exhibited smaller and thicker-walled pneumatocysts and larger blades. Overall, this study supports further investigation of depth-cycling as a macroalgal farming strategy.