Nano- and microplankton in the northern Patagonian shelf (SW South Atlantic) during austral spring and summer@en

The species composition and structure (e.g. abundance and biomass) of protistan plankton (cell size > 5 µm) and in situ chorophyll a were assessed in a shallow (<50 m depth) inner shelf area of the Argentine Shelf called El Rincón (38º-41°S). Surface water samples (5 m depth) for plankton quantification were taken with Niskin bottles during four oceanographic cruises (two in early austral spring and two in late austral summer- early fall), onboard the vessel B. Houssay accounting for a total of 36 sampling stations. These samples were analyzed under optical microscopy following the inverted microscope technique with sedimentation chambers. Cells enumeration and identification was made up to species, genus or family level, which were afterward categorized in taxonomical groups: diatoms, dinoflagellates, coccolithophores and nanoflagellates. Carbon content was calculated following the method of Menden-Deuer et al. (2000) in which biovolume was estimated assigning a geometrical shape to each species (Hillebrand et al., 1999). The biomass is the result of multiplying the carbon content of a species by its abundance in the sample. The studied area supports important fishes of commercial interest, therefore plankton biodiversity records are neccesary to understand possible shifts at the population and community levels that might have cascading effects on marine ecosystems' productivity.本数据集针对阿根廷陆架名为埃尔林孔（El Rincón）、纬度范围为南纬38°~41°的浅海近陆架区域（水深<50 m），开展了原生浮游生物（protistan plankton，细胞粒径>5 µm）的物种组成与结构（包括丰度、生物量）以及原位叶绿素a（chlorophyll a）含量的评估工作。研究依托"B. Houssay"号科考船完成4次海洋考察航次（2次于南半球初春，2次于南半球夏末至初秋），采用尼斯金采水器（Niskin bottles）采集5 m水深的表层水样用于浮游生物定量分析，共布设36个采样站位。所有水样均通过光学显微镜，采用带沉降室的倒置显微镜技术进行分析。对浮游生物进行计数与鉴定，鉴定水平可达物种、属或科层级，随后将其划分为四大分类类群：硅藻（diatoms）、甲藻（dinoflagellates）、颗石藻（coccolithophores）与纳米鞭毛藻（nanoflagellates）。碳含量参考Menden-Deuer等人（2000）的方法计算，该方法先通过为每个物种匹配几何形状以估算其生物体积（Hillebrand等人，1999）；生物量则通过单物种的碳含量与其在样品中的丰度相乘得到。该研究区域栖息有多种具备重要商业价值的鱼类，因此浮游生物多样性记录对于理解种群与群落层面可能发生的动态变化至关重要，这类变化或对海洋生态系统的生产力产生级联效应。