Departamento de Zoología y Antropología Física, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, 30100 Murcia, Spain.
Departamento de Zoología y Antropología Física, Facultad de Biología, Universidad de Murcia, Campus de Espinardo, 30100 Murcia, Spain.
Sci Total Environ. 2022 Jul 15;830:154613. doi: 10.1016/j.scitotenv.2022.154613. Epub 2022 Mar 17.
River connectivity is essential for the resilience of fish assemblages and populations and is a priority goal to reach good ecological status for river systems. Increasing knowledge on the functionality of restoration tools such as fishways is relevant for future management strategies. The present two-year assessment showed clear ecological contributions of different types of multispecies fishways in the fish assemblage of a strongly modified Mediterranean-type river. Just after their implementation, early and extended use by dominant river-resident fish of both naturelike and technical fishways were observed. All fishways were used in different seasons, especially during the migratory periods by potamodromous cyprinids, suggesting a possible use as migration corridors. Fishways also may provide compensatory habitats for small and juvenile individuals throughout the annual cycles, mostly for rheophilic fish inside nature-like bypasses and for limnophilics inside technical types. Fluvial habitat characteristics and lower flow variability inside the fishways could favour their role as a fish refuge, mainly to juveniles of cyprinids, in heavily regulated rivers where large flow fluctuations occurred. Nature-like fishways could be a better option to function as a compensatory habitat for rheophilic cyprinids in Mediterranean-type Rivers, even more because their use by large nonnative limnophilics seems to be very scarce. However, technical fishways could offer the opportunity to establish control traps of some nonnative fish, which could be of interest to reduce the risk of spreading invasive fish. Therefore, fish ecology and local hydrology should drive the decision between the types to implement. The obtained information on the ecological functionality of multispecies fishways should be considered for applying successful river restorations that are demanded by water and wildlife management schemes (e.g., the European Water Framework Directive).
河流连通性对于鱼类群落和种群的恢复力至关重要，也是实现河流系统良好生态状况的优先目标。增加对鱼类通道等恢复工具功能的了解，对于未来的管理策略具有重要意义。目前为期两年的评估表明，不同类型的多物种鱼类通道在强烈改造的地中海型河流的鱼类群落中具有明显的生态贡献。在实施后不久，就观察到自然型和技术型鱼类通道中的优势河流居留鱼类对其进行了早期和广泛的利用。所有的鱼类通道都在不同的季节被使用，特别是在洄游期间，洄游性的鲤科鱼类利用这些通道进行洄游，这表明它们可能被用作迁徙廊道。鱼类通道还可以为全年的小个体和幼鱼提供补偿性栖息地，主要是在自然型旁路中的洄游性鱼类和技术型中的底栖鱼类。河流栖息地特征和鱼类通道内较低的流量变异性可能有利于它们作为鱼类避难所的作用，特别是在流量波动较大的受高度调控的河流中，为鲤科鱼类的幼鱼提供庇护。自然型鱼类通道可能是地中海型河流中洄游性鲤科鱼类补偿性栖息地的更好选择，因为大型非本地底栖鱼类对其利用似乎非常有限。然而，技术型鱼类通道可以为建立一些非本地鱼类的控制陷阱提供机会，这对于减少入侵鱼类传播的风险可能具有重要意义。因此，鱼类生态学和当地水文学应该成为选择实施哪种类型的通道的决策依据。关于多物种鱼类通道生态功能的信息，应该在应用成功的河流恢复方面得到考虑，这些恢复是水和野生生物管理计划所要求的（例如，欧洲水框架指令）。
