We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Juvenile Salmonid Utilization of Floodplain Rearing Habitat After Gravel Augmentation in a Regulated River.
- Authors
Sellheim, K. L.; Watry, C. B.; Rook, B.; Zeug, S. C.; Hannon, J.; Zimmerman, J.; Dove, K.; Merz, J. E.
- Abstract
Gravel augmentation is used in sediment-starved streams to improve salmonid spawning habitat. As gravel is added to river channels, water surface elevations may rise in adjacent areas, activating floodplain habitat at lower flows, and floodplains inundate more frequently, potentially affecting the quantity and quality of juvenile salmonid rearing habitat. We analysed 5 years of juvenile Chinook salmon Oncorhynchus tschawytscha and steelhead Oncorhynchus mykiss data from snorkel surveys before and after gravel augmentation in the Lower American River, a low-gradient, highly regulated alluvial river in California's Central Valley. We measured the quality and quantity of rearing habitat (current velocity and areal extent of inundated riparian vegetation) following gravel placement and tested whether these factors affected juvenile abundance. Gravel augmentation increased floodplain extent by 3.7-19.8%, decreased average flow velocity from 1.6 to 0.3 m s−1 and increased the amount of vegetative cover from 0.3% to 22.6%. Juvenile abundances increased significantly for both species following augmentation. However, the strength of the relationship between abundance and habitat variables was greater for smaller salmonids. These results suggest that, in addition to enhancing salmonid spawning habitat, gravel augmentation can improve rearing habitat where channel incision and/or regulated hydrographs disconnect floodplains from main river channels. Copyright © 2015 John Wiley & Sons, Ltd.
- Subjects
CHINOOK salmon; WILDLIFE habitat improvement; WILDLIFE research; FISH farming; SALMON; SPAWNING
- Publication
River Research & Applications, 2016, Vol 32, Issue 4, p610
- ISSN
1535-1459
- Publication type
Article
- DOI
10.1002/rra.2876