Peristeraki Panagiota, Tserpes George, Lampadariou Nikolaos, Stergiou Kostantinos I
Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research, Heraklion, Crete, Greece.
Biology Department, University of Crete, Heraklion, Crete, Greece.
PLoS One. 2017 Sep 5;12(9):e0184241. doi: 10.1371/journal.pone.0184241. eCollection 2017.
Knowledge on biodiversity patterns of demersal megafaunal species in the Mediterranean and particularly in its eastern basin is still very scarce. In the present study, fine-scale diversity patterns in relation to depth were analyzed for three major megafaunal groups (fish, cephalopods and crustaceans) in three subareas of the eastern Mediterranean (Crete, Cyclades and Dodecanese islands). The analysis was based on data from the Mediterranean International Trawl Survey conducted during 2005-2014 and the relationship between depth and two different diversity measures (species richness and Shannon-Weaver) was examined using Generalized Additive Modeling (GAM) techniques. Species richness of fish decreased with depth in two of the three subareas (Cyclades, Dodecanese), while the opposite was true for crustaceans in all subareas. Cephalopods had higher species richness at intermediate depths, near the shelf break. Significant differences among subareas were found, with Crete showing a distinct species richness-depth pattern, which was more obvious for fish and cephalopods. The differences among subareas were also highlighted based on the occurrence of alien species of Indo-Pacific origin, which were more frequent in Crete. Our results suggested that the importance of depth-related factors in structuring communities was higher for cephalopods and less important for fish, and that Crete showed a distinct diversity-depth relationship, a fact that can be attributed to its specific geographical and oceanographic characteristics. These results support the current GFCM/FAO's characterization of Crete as a unique geographic subarea. The findings of the study contribute to understanding the causes of underlying diversity patterns and would assist various environmental management actions, particularly those related to the establishment of marine-protected areas.
关于地中海尤其是其东部海域底栖大型动物物种的生物多样性模式的知识仍然非常匮乏。在本研究中，分析了地中海东部三个分区（克里特岛、基克拉泽斯群岛和多德卡尼斯群岛）中三个主要大型动物类群（鱼类、头足类和甲壳类）与深度相关的精细尺度多样性模式。该分析基于2005 - 2014年期间进行的地中海国际拖网调查数据，并使用广义相加模型（GAM）技术研究了深度与两种不同多样性指标（物种丰富度和香农 - 韦弗指数）之间的关系。在三个分区中的两个（基克拉泽斯群岛、多德卡尼斯群岛），鱼类的物种丰富度随深度降低，而在所有分区中，甲壳类的情况则相反。头足类在中间深度、靠近陆架边缘处具有较高的物种丰富度。发现各分区之间存在显著差异，克里特岛呈现出独特的物种丰富度 - 深度模式，对鱼类和头足类更为明显。基于印度 - 太平洋起源的外来物种的出现情况，各分区之间的差异也得到了凸显，这些外来物种在克里特岛更为常见。我们的结果表明，与深度相关的因素在构建群落方面对头足类的重要性较高，对鱼类的重要性较低，并且克里特岛呈现出独特的多样性 - 深度关系，这一事实可归因于其特定的地理和海洋学特征。这些结果支持了目前GFCM/FAO将克里特岛描述为独特地理分区的观点。该研究结果有助于理解潜在多样性模式的成因，并将有助于各种环境管理行动，特别是那些与建立海洋保护区相关的行动。
