Mapping stable isotope gradients (isoscapes) has become a powerful tool to understand and forecast the status and variability of marine ecosystems at different levels of ecological organization. To differentiate five marine areas from the Southwest Atlantic Ocean towards oceanic and polar waters, a key foraging area for many marine consumers, we built isoscapes at different spatial scales using carbon (C) and nitrogen (N) isotope values of phytoplankton, zooplankton and particulate organic matter in sediment. We analyzed the isotopic variability between marine areas in relation with oceanographic parameters (e.g. temperature, salinity) and geographical sampling site data (e.g. latitude, longitude). We collected samples during 6 oceanographic surveys conducted in spring and autumn between 2014 and 2019 at the Beagle Channel, the Atlantic coast of Tierra del Fuego and Burdwood Bank. We included also published isotopic data of zooplankton from two other oceanic areas (the Polar Frontal Zone and Polar Antarctic Peninsula waters) to construct large-scale isoscapes. We found that the marine areas analyzed have substantially different C and N baselines; some differences exist between spring and autumn but the general pattern of isotopic variability remains similar. Combining different biological components and spatial scale analysis, isotopic variability was found to be related to variables such as seawater temperature, depth, chlorophyll and nutrients. The generated data will enhance the efficacy of isoscapes in long-term monitoring initiatives that documents alterations in attributes and features across marine expanses. This is particularly pertinent to areas under legal protection, such as the oceanic Marine Protected Areas (MPAs) established in Argentine waters.

中文翻译：

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西南大西洋至极地水域的稳定同位素空间格局


绘制稳定同位素梯度（isoscapes）已成为了解和预测不同生态组织层次的海洋生态系统状况和变异性的有力工具。为了区分从西南大西洋到大洋和极地水域（许多海洋消费者的关键觅食区域）的五个海洋区域，我们使用浮游植物、浮游动物和颗粒物的碳 (C) 和氮 (N) 同位素值在不同的空间尺度上构建了等景观沉积物中的有机质。我们分析了与海洋学参数（例如温度、盐度）和地理采样点数据（例如纬度、经度）相关的海洋区域之间的同位素变异性。我们在 2014 年至 2019 年春季和秋季在比格尔海峡、火地岛大西洋海岸和伯德伍德浅滩进行的 6 次海洋学调查中收集了样本。我们还纳入了来自其他两个海洋区域（极地锋带和极地南极半岛水域）的浮游动物的已发表同位素数据，以构建大规模等景观。我们发现所分析的海洋区域具有显着不同的 C 和 N 基线；春季和秋季之间存在一些差异，但同位素变异的总体模式仍然相似。结合不同的生物成分和空间尺度分析，发现同位素变异性与海水温度、深度、叶绿素和营养物质等变量有关。生成的数据将增强等景图在长期监测举措中的有效性，这些举措记录了整个海洋属性和特征的变化。这尤其与受法律保护的地区有关，例如在阿根廷水域建立的海洋保护区（MPA）。