17 River Geomorphology and Salmonid Habitat: Some Examples Illustrating their Complex Association, from Redd to Riverscape Scales

摘要

Given the wealth of research in recent decades on fish habitats in running waters, a review of this vast field (let alone of salmonid habitat science) would be so superficial as to be practically useless. What follows has a different and more limited ambition. This opinion piece argues for the need for geomorphologists interested in river ecosystems to develop an awareness of some of the complexities implicit in "riverine habitat", as a scientific concept. I also hope to highlight the unique contributions that river geomorphologists can make to understanding fish habitats. This will be done by illustrating typical methodological challenges incurred in research on salmonid habitats, in particular spawning habitat, using examples ranging from micro to larger "riverscape" scales. This chapter presents less a review of what we know and more a discussion of what we would like to know about salmonid habitat, along with the author's views on some of the emerging challenges in advancing on this front.