Nutrition and Growth of Large Marine Phytoplankton Species and Their Role in New Production

当代生物海洋学的一个主要挑战是调和两种相反的观点，即在开放海洋的光带中营养物质的再生是高效的，同时新的生产比以前认为的要大得多。一种假设是两个独立的生物系统并肩运作：一种是由小微生物组成的，它们能再生大部分营养物质，对新产品的贡献很小；另一种是由大型浮游植物组成的，它们以背景数量存在，在光带底部的低光水平下，随着营养物质的间歇性输入而迅速生长，然后迅速下沉。前一种制度得到了充分的研究，而后一种制度则没有。本研究的目的是在极低辐照度下研究大型浮游植物的生长和评估其在新生产中的作用。这些结果将为评估对新产量贡献巨大的大型浮游植物物种的潜力提供基础，而由于它们的生长和下沉的偶发性而被忽视。

A major challenge in contemporary biological oceanography is to reconcile the opposing arguments that nutrient regeneration in the euphotic zone of the open ocean is highly efficient, while at the same time new production is fare greater than previously believed. One hypothesis is that two separate biological systems operate side by side: one composed of small microbes that regenerate most of the nutrients and contribute little to new production and another composed of large phytoplankton species that are ever present in background numbers and that grow rapidly in response to episodic inputs of nutrients at low light levels at the base of the euphotic zone and then sink out quickly. The former system is well studied, but the latter is not. The goal of this research is to study the growth and to gauge the role of large phytoplankton species in new production at very low irradiance. The results will provide a basis for assessing the potential for large phytoplankton species contributing greatly to new production while going unnoticed because of the episodic nature of their growth and sinking.