Nature-like and conventional fishways: Alternate concepts?
fishways, structures, migration, spawning, habitat, life cycle, reproduction, fish passage, design, guidance
Journal or Book Title
Canadian Water Resources Journal
Many in-stream structures result in obstruction to fish migrations, thus preventing access to spawning grounds and other habitat areas which provide life cycle requirements for reproduction, rearing and shelter. Frequently, fishways are constructed at the site of the obstruction to provide access to habitat for various species. Conventional approaches to fish passage generally consist of 'hard' structures (e.g. concrete) or physical transport systems. Through experience and research in the laboratory and the field, much has been learned about the design requirements of these fishways. Recent attention has shifted to the use of 'soft' materials (e.g. rock), to try for a more ecologically-friendly fish passage method. The associated structures are referred to as nature-like fishways since they attempt to mimic nature. Considerable research in nature-like fishways is needed to ensure their successful application and widespread adoption. In this paper we give an overview of conventional and nature-like fish passage technology for river water projects. Included in the paper are discussions on basic fish passage requirements, conventional fishways, nature-like fishways, and guidance in selecting the fishways type. Comments are also provided on the need for further research in volitional fish passage technology.