Upgrading Fish Passage and Eflow Science and Applications

Dear Colleagues,

Many studies worldwide have documented that the construction of river obstacles (dams, small hydropower plants, weirs, etc.) have reduced fluvial continuity, and hydrological and habitat changes in streams. Impacts on aquatic biota, and particularly on fish, include the blockage of their upstream and downstream movements, degradation and fragmentation of critical habitats, fish stranding and drift due to peaking flows, increased delay in the timing of movements and mortality upon entering turbines at hydropower plants. As a result of this impairment on the upstream and downstream movements, many migratory fish populations have suffered significant declines or extinctions.

Efforts have therefore been conducted to counteract such effects. These include the upgrading of i) existing fishways for upstream movements, ii) facilities for downstream migration, including fish-friendly turbines installation and iii) environmental flow (eflow) regimes to mitigate the deleterious effects of flow regime alterations and protect and restore river ecosystems, as well as their critical environmental services and cultural/societal values. Efficient fishways allow fish to negotiate, with minimum delay, physical instream obstacles, such as weirs and dams, to move to spawning, feeding or refuge habitats. Downstream migration facilities may include physical, mechanical and behavioural devices or combinations among them, capable of diverting fish away from turbines and guiding them towards safer alternative routes, such as bypasses. Eflow regimes setting and refinement stands as the most valid approach to sustain both human water uses and protection of freshwater ecosystems. Many methodologies, from the simplest calculations based only on hydrological data, to the most complex ones based on hydrodynamic and habitat modeling, including sediment transport and riparian vegetation modelling, and incorporating socio-economic conditions, are available for eflow regime definition, and their selection and final decision for a specific site is still a challenging job. The installation of equipment to release newly set eflow regimes in existing dams may be a challenging task as well.

This Special Issue aims to compile new information on fundamental scientific research and applications regarding fish passage and eflows (check keyword research topics below), ranging from field studies to laboratory experiments to case-study applications challenges, with emphasis for upgrading interventions. The goal is to provide an updated and broad perspective of the current developments in this field and to promote the knowledge interchange and discussion about future research directions.

Prof. Dr. António Pinheiro
Dr. José Maria Santos
Dr. Maria João Costa
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• dams and weirs
• aquatic ecosystems
• upstream and downstream mitigation measures
• fishways
• eflows
• hydropeaking
• riparian vegetation
• river restoration
• climate change
• habitat modelling
• building block method
• behavioural barriers
• louvers
• bar-racks
• bypasses
• fish-friendly turbines