The Effect of Mesoscale Eddies on Phytoplankton Community Structure, Total Production, and the F Ratio in Open Ocean Waters

夏威夷群岛附近形成的中尺度气旋涡旋将被用来研究上升流事件对公海浮游植物种群的生产力，组成，生物量和生理的影响。将利用最新的技术和方法进步，更准确地确定新生产量与总生产量的比率（f比率）以及该比率在开阔洋的时间和空间变化。简单的经验模型和更复杂的房室模型都将被测试其描述和解释所观察到的f比变化的能力。将使用最近开发的硝酸盐分析方法获得新产量的估计值，精确度为+/- 2nM。总产量将通过将C-14标记的无机碳掺入蛋白质中来估计。这种实验方法将消除与传统f-比率研究相关的许多潜在人为因素和问题，包括由添加非示踪剂量的N-15引起的扰动、基质池的同位素稀释、测量环境基质浓度的困难、测量至少三种形式的溶解N的吸收的需要，以及细菌可能占铵吸收的很大一部分的事实。海洋的生物生产力在地理上有很大的差异。在中盆地亚热带地区，如夏威夷群岛附近，产量通常相对较低。然而，当地沃茨的物理特征，例如在岛屿西部发现的圆形漩涡，可以通过增加对表面沃茨的植物生长的营养供应来提高生产力。Laws和Bienfang将使用最先进的技术来测量生物生产中的这些变化，并将其与生物群落的结构联系起来。他们将对新的产量进行敏感的测量，这是一个对估计来自地表沃茨的有机物质通量及其可收获资源的可用性至关重要的参数。在发现海洋涡旋的地区进行研究，将提供可能在公海发现的各种生物海洋学条件。

Mesoscale Cyclonic Eddies Formed Near the Hawaiian Islands will be utilized to study the effects of upwelling events on the productivity, composition, biomass, and physiology of open-ocean phytoplankton populations. Recent technical and methodological advances will be utilized to more accurately determine the ratio of new production to total production (f-ratio) and the temporal and spatial variability of that ratio in the open ocean. Both simple empirical models and more sophisticated compartmental models will be tested for their ability to describe and explain observed f-ratio variations. Estimates of new production will be obtained using a recently developed nitrate analysis method with a precision of +/- 2nM. Total production will be estimated from the incorporation of C-14 labeled inorganic carbon into protein. This experimental approach will eliminate many of the potential artifacts and problems associated with traditional f-ratio studies, including perturbations caused by the addition of non- tracer amounts of N-15, isotope dilution of the substrate pool, difficulty in measuring ambient substrate concentrations, the need to measure uptake of at least three forms of dissolved N, and the fact that bacteria may account for a significant fraction of the uptake of ammonium. The biological productivity of the ocean varies geographically to a great degree. In mid-basin subtropical areas such as thevicinity of the Hawaiian Islands, production is typically relatively low. However, physical features of the local waters such as the circular eddies found to the west of the islands can enhance productivity by increasing the supply of nutrients for plant growth to surface waters. Laws and Bienfang will use state of the art techniques to measure these variations in biological production and relate it to the structure of the planktonic community. They will make sensitive measurements of new production, a parameter that is critical in estimating the flux of organic material from surface waters and its availability for harvestable resources. Conducting the studies in an area where oceanic eddies are found will provide a wide range of biological oceanographic conditions likely to be found in the open ocean.