Abstract Mesozooplankton composition including functional groups in relation to hydrological features is studied in the oligotrophic pelagic ecosystem of the eastern Mediterranean Sea. Combining classic/standard microscopy and advanced digital imaging approach copepod growth rates, ingestion and production rates were estimated using allometric relationships. For this purpose, mesozooplankton samples were taken in the epipelagic zone (0–200 m) in June 2016, over a grid of 16 stations in the Cretan Sea, the Cretan Passage and the eastern and western Cretan Straits including one station in the Mirtoan Sea. The sampling area is influenced by the presence of the permanent Rhodes Cyclonic Gyre east of Crete and a series of smaller permanent or recurrent gyres south of Crete that influence the anti-estuarine pathway of the Atlantic Water from the Ionian Sea towards the Levantine Basin at surface and subsurface layers. Mesozooplankton abundance exhibited almost similar values (mean value 312 ind m−3 ± 100 SD) among transects with a higher value at the western Straits (up to 562 ind m−3). Copepods were the dominant group at all stations with almost the same relative contributions among stations (76%) but slightly higher values in the Cretan Passage. The contribution of copepod functional groups in the mesozooplankton community is also highlighted. The importance of small sized copepods was underlined by small ambush feeding carnivores, prevailing at all stations and demonstrating a high degree of opportunistic feeding of copepods in these ultra-oligotrophic waters, with chlorophyll a ranging from 0.05 to 0.20 μg L−1. Copepod vital rates (production, ingestion and respiration) estimated by a growth rate model were generally low, with higher values in the Cretan Sea.

中文翻译：

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东地中海中浮游动物群落结构

摘要 在地中海东部的贫营养远洋生态系统中研究了包括与水文特征相关的功能组在内的中浮游生物组成。结合经典/标准显微镜和先进的数字成像方法，使用异速生长关系估计桡足类的生长速率、摄取和生产率。为此，于 2016 年 6 月在上层浮游区（0-200 m）采集了中浮游生物样本，分布在克里特海、克里特海峡和克里特海峡东部和西部的 16 个站点的网格中，其中一个站点位于米尔托安海. 采样区域受到克里特岛以东的永久罗得斯气旋环流和克里特岛以南一系列较小的永久或循环环流的影响，这些环流影响大西洋水从爱奥尼亚海到地表黎凡特盆地的反河口通道和地下层。中浮游动物丰度在海峡西部具有较高值（高达 562 ind m-3）的断面中表现出几乎相似的值（平均值 312 ind m-3 ± 100 SD）。桡足类是所有站点的主要类群，站点之间的相对贡献几乎相同（76%），但在克里特海峡中的值略高。桡足类功能群在中浮游生物群落中的贡献也得到了强调。小型伏击食肉动物强调了小型桡足类动物的重要性，在所有站点普遍存在，并证明了在这些超贫营养水域中桡足类的高度机会性摄食，叶绿素 a 范围为 0.05 至 0.20 μg L-1。生长速率模型估计的桡足类生命率（生产、摄取和呼吸）通常较低，克里特海的数值较高。