Abstract

Patterns of juvenile salmonid movement in natal streams provide insight into factors driving movement and ways to develop proactive conservation practices for wild salmon populations. This work expands on years of ongoing investigations for a comprehensive understanding of landscape and habitat characteristics important for salmon success. This study ties into an existing model for headwater streams in the Kenai Lowlands which predicts the presence of juvenile coho salmon and Dolly Varden by age-class based on catchment topography, wetland geomorphology, water chemistry, substrate composition, channel morphology, and macroinvertebrate and fish communities (King et al. 2012). We tagged nearly 1,000 juvenile coho salmon (Onchorynchus kisutch) and Dolly Varden char (Salvelinus malma) with passive integrated transponder (PIT) tags in headwater streams with varying gradients and habitat conditions in the Kenai Lowlands, Alaska from May to October 2012, and tracked their movement with stationary antenna arrays spaced approximately 0.8 - 3.5 km apart. Our results demonstrate that juvenile salmonids moved considerably in rearing habitat during non-migratory periods (e.g. seaward migrations), conceivably in an exploratory nature to find optimal habitat. Larger juveniles appeared to move more than smaller juveniles. Our results suggest that stream temperature, stage and time of year may be correlated to summer movement in headwater streams. Most fish were detected again within their site of capture moving 5 - 10 m, and 23 % of tagged fish moved distances of 0.8 - 3.5 km to another site. This novel finding is important, because we now know that fish are moving between habitats at different reach levels. The movement of fish between reaches and the utilization of different habitats emphasizes the importance of habitat heterogeneity and connectivity between diverse shelter and foraging habitats during pre-smolt stages. Further investigation into habitat use by juvenile salmonids during different seasons may clarify species- and age-class specific patterns of movement.

Library of Congress Subject Headings

Salmon--Home range--Alaska; Chars--Home range--Alaska; Salmon--Infancy; Chars--Infancy

Publication Date

7-31-2013

Document Type

Thesis

Department, Program, or Center

Thomas H. Gosnell School of Life Sciences (COS)

Advisor

Tyler, Anna

Advisor/Committee Member

Walker, Coowe

Advisor/Committee Member

Pagano, Susan

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: QL638.S2 B47 2013

Campus

RIT – Main Campus

Plan Codes

ENVS-MS

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