- Poor growth and survival in freshwater and marine environments have been implicated as responsible for Chinook salmon (Oncorhynchus tshawytscha) declines across Alaska.
- Lateral connectivity of river main stems with off-channel habitats may play an integral role in sustaining Alaskan salmonid populations because off-channel habitats commonly provide greater growth opportunities than main stem habitats through greater macroinvertebrate productivity and warmer water temperatures. However, off-channel habitats may impose greater mortality risks to juvenile salmonids, as these habitats are typically more susceptible to drying and are often occupied by potential predators.
- We used a hierarchical Bayesian count model to describe juvenile Chinook salmon distributions throughout the Chena River, Alaska in main stem and off-channel habitats and employed diet, prey availability, and bioenergetic analyses to explain these habitat selection decisions from data collected in the summer of 2015.
- We found salmon to be most abundant in off-channel habitats as summer temperature increased, which suggested that salmon dispersed to off-channel habitats to take advantage of energetically favourable growth conditions as indicated by the higher prey biomass in benthic and diet samples collected within off-channel habitats.
- Our results could have significant implications for juvenile salmon under a warming Alaskan climate as access to productive off-channel habitats may be important to offset increased energetic costs as temperature warms.
|Title||Main stem and off-channel habitat use by juvenile Chinook salmon in a sub-Arctic riverscape|
|Authors||Brock M. Huntsman, Jeffrey A. Falke|
|Publication Subtype||Journal Article|
|Series Title||Freshwater Biology|
|Record Source||USGS Publications Warehouse|
|USGS Organization||Coop Res Unit Seattle|
Jeff Falke, PhD
Jeff Falke, PhD