Highly mobile organisms can transport nutrients and energy among distinct ecosystems, such as between oceanic foraging areas and terrestrial breeding sites. Seabirds are great nutrient carriers and potentially play a key role in the maintenance of trophic webs on islands. In this study, we assessed three dimensions of marine nutrient dissipation—horizontal, temporal and vertical—on the tropical Meio Island of Fernando de Noronha Archipelago, Brazil. For this, C₃ and C₄ plants, ants and spiders found in a 100 m long transect between colonies of masked (Sula dactylatra) and red-footed boobies (Sula sula) were sampled during the rainy (the masked booby breeding period) and dry seasons (the red-footed booby breeding period). The marine contribution to the terrestrial trophic web was analysed using Bayesian mixing models from a carbon and nitrogen stable isotope data set. The main findings indicate that marine nutrients in the terrestrial trophic web dissipated horizontally as the distance from the colony increased, which was more marked during the rainy season. On the vertical axis, the relative contribution of marine nutrients in terrestrial consumers was strongly related to food habits but not necessarily to the trophic level, dissipating rather than increasing, due to variable omnivory and the use of terrestrial food sources. The breeding strategy of the masked booby (i.e. incubating eggs on the ground), in addition to a larger body size and larger colony, could produce a more concentrated pulse of nutrients in comparison to seabirds nesting sparsely on trees, contributing more efficiently to the enrichment of marine nutrients on land. The importance of seabirds for the maintenance of interconnected ecosystems has been demonstrated, and the role of marine-derived nutrients in the enrichment of nutrient-poor tropical islands.

中文翻译：

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陆地岛屿营养网中海鸟衍生营养物质的消散

高度移动的生物可以在不同的生态系统之间运输养分和能量，例如在海洋觅食区和陆地繁殖地之间。海鸟是很好的营养载体，可能在维护岛屿上的营养网中发挥关键作用。在这项研究中，我们评估了巴西费尔南多·德·诺罗尼亚群岛热带梅奥岛的海洋养分消散的三个维度——水平、时间和垂直。为此，在蒙面鲣鸟 (Sula dactylatra _)和红脚鲣鸟 ( Sula sula) 在雨季（蒙面鲣鸟繁殖期）和旱季（红脚鲣鸟繁殖期）进行采样。使用来自碳和氮稳定同位素数据集的贝叶斯混合模型分析了海洋对陆地营养网的贡献。主要研究结果表明，随着与殖民地距离的增加，陆地营养网中的海洋养分水平消散，这在雨季更为明显。在纵轴上，由于杂食性的变化和陆地食物来源的使用，海洋营养素对陆地消费者的相对贡献与饮食习惯密切相关，但不一定与营养水平有关，消散而不是增加。蒙面鲣鸟的繁殖策略（即在地上孵蛋），除了更大的体型和更大的群落之外，与稀疏地筑巢在树上的海鸟相比，它还可以产生更集中的营养脉冲，从而更有效地促进陆地上海洋营养物质的富集。海鸟对维持相互关联的生态系统的重要性已得到证实，海洋来源的营养物质在富集营养贫乏的热带岛屿方面的作用已得到证实。