Keller Stefanie, Bartolino Valerio, Hidalgo Manuel, Bitetto Isabella, Casciaro Loredana, Cuccu Danila, Esteban Antonio, Garcia Cristina, Garofalo Germana, Josephides Marios, Jadaud Angelique, Lefkaditou Evgenia, Maiorano Porzia, Manfredi Chiara, Marceta Bojan, Massutí Enric, Micallef Reno, Peristeraki Panagiota, Relini Giulio, Sartor Paolo, Spedicato Maria Teresa, Tserpes George, Quetglas Antoni
Instituto Español de Oceanografía, Centro Oceanográfico de Baleares, Muelle de Poniente, s/n, Apdo. 291, 07015 Palma de Mallorca, Spain.
SLU Swedish University of Agricultural Sciences, Department of Aquatic Resources, Lysekil, Sweden.
PLoS One. 2016 Jan 13;11(1):e0146469. doi: 10.1371/journal.pone.0146469. eCollection 2016.
Species diversity is widely recognized as an important trait of ecosystems' functioning and resilience. Understanding the causes of diversity patterns and their interaction with the environmental conditions is essential in order to effectively assess and preserve existing diversity. While diversity patterns of most recurrent groups such as fish are commonly studied, other important taxa such as cephalopods have received less attention. In this work we present spatio-temporal trends of cephalopod diversity across the entire Mediterranean Sea during the last 19 years, analysing data from the annual bottom trawl survey MEDITS conducted by 5 different Mediterranean countries using standardized gears and sampling protocols. The influence of local and regional environmental variability in different Mediterranean regions is analysed applying generalized additive models, using species richness and the Shannon Wiener index as diversity descriptors. While the western basin showed a high diversity, our analyses do not support a steady eastward decrease of diversity as proposed in some previous studies. Instead, high Shannon diversity was also found in the Adriatic and Aegean Seas, and high species richness in the eastern Ionian Sea. Overall diversity did not show any consistent trend over the last two decades. Except in the Adriatic Sea, diversity showed a hump-shaped trend with depth in all regions, being highest between 200-400 m depth. Our results indicate that high Chlorophyll a concentrations and warmer temperatures seem to enhance species diversity, and the influence of these parameters is stronger for richness than for Shannon diversity.
物种多样性被广泛认为是生态系统功能和恢复力的一个重要特征。了解多样性模式的成因及其与环境条件的相互作用对于有效评估和保护现有多样性至关重要。虽然鱼类等大多数常见类群的多样性模式通常会被研究，但头足类等其他重要分类群受到的关注较少。在这项工作中，我们展示了过去19年整个地中海头足类多样性的时空趋势，分析了由5个不同地中海国家使用标准化渔具和采样协议进行的年度底拖网调查MEDITS的数据。使用广义相加模型，以物种丰富度和香农-维纳指数作为多样性描述指标，分析了地中海不同区域局部和区域环境变异性的影响。虽然西部海域显示出高多样性，但我们的分析并不支持先前一些研究中提出的多样性自西向东稳步下降的观点。相反，在亚得里亚海和爱琴海也发现了高香农多样性，在爱奥尼亚海东部发现了高物种丰富度。在过去二十年中，总体多样性没有呈现出任何一致的趋势。除了亚得里亚海，所有区域的多样性随深度呈驼峰状趋势，在200 - 400米深度之间最高。我们的结果表明，高叶绿素a浓度和较高温度似乎会提高物种多样性，并且这些参数对丰富度的影响比对香农多样性的影响更强。
