Department of Biology, Institute of Marine Research (INMAR), University of Cádiz, 11510, Puerto Real, Cádiz, Spain.
Marine Research Center, University of Vigo, Geoma, 36310, Vigo, Spain.
Mar Environ Res. 2024 Feb;194:106333. doi: 10.1016/j.marenvres.2023.106333. Epub 2024 Jan 1.
Antarctic benthic ecosystems support a unique fauna characterized by high levels of diversity and endemism. However, our knowledge of the macrofauna communities across the Antarctic intertidal sedimentary shore is limited, and their fundamental ecological features, including spatial variability, remain poorly understood. This study aimed to investigate the abundance, community structure (i.e. taxa-specific abundance), and biodiversity patterns (α-, β-, and λ-diversity) of benthic macrofauna communities on intertidal sedimentary shores of two Antarctic islands (South Shetland archipelago, N of Antarctic Peninsula): Livingston and Deception. We conducted a quantitative sampling during two Austral summer campaigns (2004 and 2005), studying eleven intertidal sites, with five sites located on Livingston and six on Deception. Our results demonstrated a significantly higher abundance of intertidal benthic macrofauna communities on Livingston than on Deception. Furthermore, significant differences in community structure were observed between the two islands. In terms of biodiversity patterns, there were no significant differences in the number of taxa within communities (α-diversity) between the two islands. However, significant differences in the variation of community composition (determined by the number and identity of taxa) between intertidal sites (β-diversity) were observed, shedding light on the higher total taxa count (λ-diversity) on Livingston compared to Deception. We suggest that the island-specific characteristics (e.g., granulometric characteristics, ice disturbance, sedimentation rates, and geothermal activity) determine the differences observed in macrofauna communities. However, other ecological processes and factors are operating on different spatial and temporal scales (e.g., population dynamics, biotic interactions, oceanographic conditions, and climate change) that influence the occurrence and abundance of macrofaunal taxa. Our findings contribute to the fundamental understanding of the spatial variability of these communities and provide essential information for better management decisions and conservation practices in Antarctic coastal ecosystems.
南极底栖生态系统支持着具有高度多样性和特有性的独特动物群。然而，我们对整个南极潮间带沉积性海岸的大型动物群群落的了解是有限的，其基本生态特征，包括空间变异性，仍未得到很好的理解。本研究旨在调查南极两个岛屿（南极半岛北部的南雪特兰群岛）的潮间带沉积性海岸上底栖大型动物群群落的丰度、群落结构（即特定类别的丰度）和生物多样性模式（α-、β-和 λ-多样性）。我们在两个南极夏季（2004 年和 2005 年）进行了定量采样，研究了 11 个潮间带地点，其中 5 个地点位于利文斯顿，6 个位于欺骗岛。我们的结果表明，利文斯顿的潮间带底栖大型动物群群落的丰度明显高于欺骗岛。此外，两个岛屿之间的群落结构也存在显著差异。在生物多样性模式方面，两个岛屿之间的群落内的分类单元数量（α-多样性）没有显著差异。然而，潮间带地点之间的群落组成变化（由分类单元的数量和身份决定）存在显著差异，这表明利文斯顿的总分类单元计数（λ-多样性）明显高于欺骗岛。我们认为，岛屿特有的特征（例如，粒度特征、冰干扰、沉积率和地热活动）决定了观察到的大型动物群群落之间的差异。然而，其他生态过程和因素在不同的空间和时间尺度上起作用（例如，种群动态、生物相互作用、海洋学条件和气候变化），这些因素影响着大型动物群分类单元的发生和丰度。我们的研究结果有助于深入了解这些群落的空间变异性，并为更好地管理决策和保护南极沿海生态系统提供必要的信息。
