Data underlying the publication: "Environmental requirements and heterogeneity of rheophilic fish nursery habitats in European lowland rivers: current insights and future challenges"

The large-scale degradation of riparian ecotones and of the connectivity between rivers and their floodplains has resulted in a drastic decline of rheophilic fish populations in European temperate lowland rivers. Recent river restoration projects have had variable success in effectively restoring these fish populations. Knowledge on nursery habitat requirements is considered essential for effective population restoration. However, a detailed understanding of the role of habitat heterogeneity in young-of-the-year (YOY) fish population development is limited. Therefore, we carried out a synthesis of the available knowledge on nursery habitat requirements of rheophilic fish species found in European temperate lowland rivers (<200 m elevation). From a total of 603 papers, 77 studies with primary information were selected, containing 390 associations between habitat features and YOY fish. As expected, most studies focused on static components of physical riparian habitat. Generally, YOY fish require habitats of shallow depth (<0.5 m), with slow-flowing water (<0.2 m·s-1), gentle bank slope (<20 degrees), variety in substratum types (fine sand to gravel), relatively warm water, and high food availability. Surprisingly, no clear ontogenetic habitat shifts between larvae and juveniles were found, which may be explained by the limited spatial-temporal resolution of most studies. Since 2011, studies on habitat heterogeneity have increased, but few have explicitly assessed its role in relation to movement patterns of YOY fish for nursery success. Therefore, we recommend that future research focuses on fish movement patterns between habitat patches in heterogeneous (river-floodplain) environments, to increase the knowledge base for effective recovery of rheophilic fish populations.

河岸生态交错带（riparian ecotones）与河流及其泛滥平原之间连通性的大规模退化，已导致欧洲温带低地河流中嗜流水性鱼类（rheophilic fish）种群急剧下降。近年来的河流修复项目在有效恢复此类鱼类种群方面成效参差不齐。学界普遍认为，掌握育幼栖息地（nursery habitat）需求是实现种群有效修复的核心前提。然而，针对栖息地异质性（habitat heterogeneity）在当年生幼鱼（young-of-the-year, YOY）种群发展中所发挥作用的深入认知仍较为有限。为此，我们对海拔低于200米的欧洲温带低地河流中嗜流水性鱼类的育幼栖息地需求相关现有研究成果进行了综合梳理。在总计603篇文献中，筛选出77项包含一手原始数据的研究，共涵盖390组栖息地特征与当年生幼鱼的关联分析结果。正如预期，多数研究聚焦于河岸物理栖息地的静态组成要素。总体而言，当年生幼鱼偏好栖息于水深较浅（<0.5 m）、水流缓慢（<0.2 m·s⁻¹）、岸坡平缓（<20°）、底质类型多样（从细沙到砾石）、水温相对偏高且食物资源丰富的区域。令人意外的是，研究未发现当年生幼鱼在仔鱼与稚鱼阶段间存在明确的个体发育栖息地转移（ontogenetic habitat shift），这一现象或许可归因于多数研究在时空分辨率上的局限性。自2011年以来，有关栖息地异质性的研究数量有所增加，但极少有研究明确评估其与当年生幼鱼移动模式之间的关联对育幼成效的影响。因此，我们建议未来研究应聚焦于异质性（河流-泛滥平原）环境中不同栖息地斑块间的鱼类移动模式，以夯实嗜流水性鱼类种群有效恢复的知识基础。