Abstract The influence of oceanographic fronts on the abundance and community composition of invertebrate larvae, mostly of benthic species, along nearly 2000 km of the southwestern Atlantic shelf (21–34°S) was investigated. Meroplankton was sampled through vertical hauls at 89 stations, distributed along 14 cross-shelf transects, during late spring 2010 and early summer 2011. Salinity and temperature were registered with a CTD/rosette system, which provided seawater for chlorophyll-a and nutrient concentrations estimations. Vertical profiles of temperature, salinity, chlorophyll-a and nutrients were used as proxies of the fronts. In addition, high-resolution thermosalinograph data were used to detect surface frontal features. Meroplankton abundance peaks were found at several fronts intersected by the ship, including upwelling zones, estuarine and plume fronts, a shelf-break front, and two cyclonic eddies. Furthermore, meroplankton abundance was also relatively higher at small-scale thermal and/or saline surface fronts observed along the shelf. Such increases in meroplankton abundance are likely to be ascribed to high nutrient input and primary production. Distinct taxa of invertebrate larvae occurred at different types of fronts, besides the coastal realm, which was virtually dominated by decapod, cirripede and bivalve larvae. Small-scale shelf fronts presented high abundances of decapod and gastropod larvae, for instance, while larvae of polychaetes were the most frequent in the estuarine front of Patos Lagoon section.

中文翻译：

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沿南巴西陆架海洋前沿的浮游生物群落结构

摘要 研究了海洋前沿对大西洋西南大陆架（21-34°S）近 2000 公里无脊椎动物幼虫（主要是底栖物种）的丰度和群落组成的影响。在 2010 年春末和 2011 年初夏期间，通过沿 14 个跨大陆架横断面分布的 89 个站的垂直运输对浮游生物进行采样。 盐度和温度通过 CTD/玫瑰花结系统进行记录，该系统为叶绿素 a 和养分浓度估计提供了海水. 温度、盐度、叶绿素-a 和营养物的垂直剖面被用作锋面的代理。此外，高分辨率热盐度仪数据用于检测表面正面特征。在与船相交的几个前沿发现了浮游生物丰度峰值，包括上升流区，河口和羽流锋、断架锋和两个气旋涡旋。此外，在沿陆架观察到的小尺度热和/或盐表面前沿处，浮游生物丰度也相对较高。浮游生物丰度的这种增加可能归因于高营养输入和初级生产。无脊椎动物幼虫的不同分类群出现在不同类型的前沿，除了沿海地区，几乎以十足目、卷足类和双壳类幼虫为主。例如，小规模的陆架前沿呈现出丰度高的十足目和腹足动物幼虫，而多毛类幼虫在帕托斯泻湖部分的河口前沿最为常见。在沿大陆架观察到的小尺度热和/或盐表面前沿处，浮游生物的丰度也相对较高。浮游生物丰度的这种增加可能归因于高营养输入和初级生产。无脊椎动物幼虫的不同分类群出现在不同类型的前沿，除了沿海地区，几乎以十足目、卷足类和双壳类幼虫为主。例如，小规模的陆架前沿呈现出丰度高的十足目和腹足动物幼虫，而多毛类幼虫在帕托斯泻湖部分的河口前沿最为常见。在沿大陆架观察到的小尺度热和/或盐表面前沿处，浮游生物的丰度也相对较高。浮游生物丰度的这种增加可能归因于高营养输入和初级生产。无脊椎动物幼虫的不同分类群出现在不同类型的前沿，除了沿海地区，几乎以十足目、卷足类和双壳类幼虫为主。例如，小规模的陆架前沿呈现出丰度高的十足目和腹足动物幼虫，而多毛类幼虫在帕托斯泻湖部分的河口前沿最为常见。除了沿海地区，这里实际上以十足目动物、卷足类和双壳类幼虫为主。例如，小规模的陆架前沿呈现出丰度高的十足目和腹足动物幼虫，而多毛类幼虫在帕托斯泻湖部分的河口前沿最为常见。除了沿海地区，这里实际上以十足目动物、卷足类和双壳类幼虫为主。例如，小规模的陆架前沿呈现出丰度高的十足目和腹足动物幼虫，而多毛类幼虫在帕托斯泻湖部分的河口前沿最为常见。