Abstract Riverine fish conservation in eco‐hydraulics is often based on restoring or regulating river habitat to a semi‐natural state. For example, ecohydraulic projects support fish populations by increasing river connectivity through fishways, and by maintaining or restoring natural flow variance to enhance habitat quality and availability. However, the application of these concepts is challenging due to climate change and human perturbations that can modify the riverine environment in unpredictable ways. To address these challenges, we propose broadening eco‐hydraulics to eco‐evo‐hydraulics by incorporating the evolutionary dynamics of fish populations into eco‐hydraulics. We argue that this may improve the resilience and resistance of fish populations to future climate and human perturbation. Moreover, the evolutionary response of fishes to perturbations also alters their capability to “zoogeomorphically engineer” their physical environment, with associated feedbacks such as changes in sediment mobilization. Thus, understanding such hydro‐evolutionary feedbacks can improve the long‐term prediction of river hydraulics. In this position paper, we explore the interactions between hydraulics, hydrology, and rapid evolution based on a literature review to identify gaps and opportunities that need joint efforts from water resources engineers and evolutionary biologists. We propose the concept of eco‐evo‐hydraulics with hydro‐evolutionary feedbacks to encapsulate the interactions between the three disciplines, and suggest research avenues for the future. Finally, we suggest potential managerial strategies based on the eco‐evo‐hydraulic concept for local and basin‐wide fish conservation. We aim to fill the gap between water resources management and evolutionary biology to provide a new theory for fish conservation.
Cai et al. (Wed,) studied this question.