Marine Primary Producers >20uM from the Eastern Equatorial Pacific: Quantitative Estimates and Taxonomic Analysis for U.S. JGOFS

20微米大小的海洋浮游植物比较小的组分下沉得更快，是全球通过海洋水柱向沉积物的通量中要考虑的一个重要的大小。为了了解赤道太平洋20微米浮游植物的丰度和生物量，将通过JGOFS EQPAC季节性邮轮的多次开网和闭网采集以及水瓶样品进行研究。优先考虑赤道以北和以南20个区域内的两次季节性时间序列巡航，该区域是已知向沉积物输送物质最多的区域。网状浮游生物将通过一个多个开放和关闭的新系统从不同的地层集中，该系统将部署在选定的深度，以补充类似的浮游动物采样计划，并集中来自上层的浮游植物，并在被确定为生物地球化学非常活跃的深度区域的真光带下方集中浮游植物。季节性调查巡航将允许从水瓶样本和垂直网状物中对较大的浮游植物进行经向解释。较大的硅藻和甲藻是所遇到的不同水团的良好指标，在赤道水中发现的硅化程度较高的硅藻物种的生活史和垂直分带将被用来测试硅化程度与高纬度水域中的生长限制条件之间的可能关系。

The 20 um size fraction of marine phytoplankton sinks faster than smaller components and is an important size fraction to consider in global flux out of the euphotic zone through the oceanic water column to the sediments. In order to understand the abundance and biomass of the 20 um phytoplankton in the equatorial Pacific, multiple opening and closing net collections as well as water bottle samples will be studied through this program from the seasonal JGOFS EQPAC cruises. The priority will be to 2 seasonal time-series cruises within 20 north and south of the equator in the area known to have the greatest flux of material to the sediments. The netplankton will be concentrated from different strata by a multiple opening and closing new system deployed at depths chosen to complement a similar zooplankton sampling scheme as well as to concentrate phytoplankton from the upper surface layers and just below the euphotic zone in a depth region identified as very active biogeochemically. The seasonal survey cruises will allow meridional interpretations of the larger phytoplankton from water bottle samples and vertical net hauls. The larger diatoms and dinoflagellates are excellent indicators of the different water masses encountered, and the life histories and vertical zonation of the more heavily silicified diatom species found in equatorial water will be used to test a possible relationship between degree of silicification and growth-limiting conditions seen in higher latitude waters.