1. The European Natura 2000 (N2K) network of protected areas stands out as the main conservation strategy in the European Union to preserve biodiversity under the auspices of the Convention on Biological Diversity.
2. The management of N2K sites is mainly focused on protecting the biological elements as Special Areas of Conservation for habitats or species listed in the European Habitats Directive, or as Special Protection Areas for birds listed in the European Birds Directive for which the site was designated. It seems urgent, therefore, to discriminate which N2K sites are really providing effective protection for aquatic biodiversity.
3. Although the main objective of N2K is to protect species listed in the Birds and Habitats Directives, the conservation status of threatened species included in the European Red List of the IUCN must also be a concern for the European Union.
4. Focusing on Central Spain as a case study, the aim of this work was to evaluate how far aquatic N2K (i.e. N2K sites designated for the occurrence of freshwater elements) is effective in protecting both those aquatic species in the Directives [referred to here as Species of Community Importance (SCI) and threatened species (TS)].
5. Most of the N2K sites in the study area have been designated using aquatic elements, which means that N2K could theoretically provide appropriate mechanisms to preserve aquatic biodiversity. However, N2K provides a low percentage of overlap with some of the hotspots identified for both TS and SCI. Surprisingly, TS are in general similarly or even better represented than SCI by N2K.
6. N2K may provide good coverage for aquatic biodiversity, mainly by acting as an umbrella for other species, but it could be improved by addressing some spatial gaps, thereby making it more relevant to current challenges such as climate change and other human impacts.

中文翻译：

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评估 Natura 2000 水生网络在保护地中海地区具有共同利益的欧洲淡水物种和受威胁物种方面的作用

1. 欧洲自然 2000 (N2K) 保护区网络是欧盟在《生物多样性公约》主持下保护生物多样性的主要保护战略。
2. N2K 场地的管理主要侧重于保护生物元素，作为欧洲栖息地指令中列出的栖息地或物种的特殊保护区，或作为该场地指定的欧洲鸟类指令中列出的鸟类的特殊保护区。因此，区分哪些 N2K 站点真正为水生生物多样性提供有效保护似乎很紧迫。
3. 虽然 N2K 的主要目标是保护鸟类和栖息地指令中列出的物种，但列入 IUCN 欧洲红色名录的受威胁物种的保护状况也必须成为欧盟关注的问题。
4. 以西班牙中部作为案例研究，这项工作的目的是评估水生 N2K（即指定用于发生淡水元素的 N2K 地点）在保护指令中的这两种水生物种方面的有效程度 [此处称为物种社区重要性 (SCI) 和受威胁物种 (TS)]。
5. 研究区域内的大多数 N2K 地点都被指定为使用水生元素，这意味着 N2K 理论上可以提供适当的机制来保护水生生物多样性。然而，N2K 与为 TS 和 SCI 确定的一些热点提供了低百分比的重叠。令人惊讶的是，TS 通常与 N2K 的 SCI 相似甚至更好。
6. N2K 可以很好地覆盖水生生物多样性，主要是作为其他物种的保护伞，但可以通过解决一些空间差距来改善它，从而使其与气候变化和其他人类影响等当前挑战更相关。