Comparison of Site Fidelity and Growth Rates of Juvenile Salmon between two Stream Types - A Pilot Study
Dates
Year
2010
Citation
Davis, Jeffrey C., and Davis, Gay A., 2010, Comparison of Site Fidelity and Growth Rates of Juvenile Salmon between two Stream Types - A Pilot Study: Aquatic Restoration and Research Institute: Talkeetna, Alaska, p. 15-15.
Summary
A pilot study was conducted to evaluate the use of PIT tags and underwater antennas to measure juvenile salmon growth rates and site fidelity. Juvenile coho (Oncorhynchus kisutch) and Chinook salmon (Oncorhynchus tshawytsha) growth rates and site fidelity were compared between two streams within the Susitna River drainage in Southcentral Alaska. The two study streams were selected to represent a low-sloped wetland stream which is common on the west side of the drainage and a moderate sloped upland stream that drains the Talkeetna mountains which is common on the east side of the drainage. Comparisons of growth rates and site fidelity within these two streams were used to test for the differences in the habitat quality between stream [...]
Summary
A pilot study was conducted to evaluate the use of PIT tags and underwater antennas to measure juvenile salmon growth rates and site fidelity. Juvenile coho (Oncorhynchus kisutch) and Chinook salmon (Oncorhynchus tshawytsha) growth rates and site fidelity were compared between two streams within the Susitna River drainage in Southcentral Alaska. The two study streams were selected to represent a low-sloped wetland stream which is common on the west side of the drainage and a moderate sloped upland stream that drains the Talkeetna mountains which is common on the east side of the drainage. Comparisons of growth rates and site fidelity within these two streams were used to test for the differences in the habitat quality between stream types. Juvenile salmon were captured in mid August 2009 from two 100-m reaches in each stream. Positive integrated transponder tags were inserted into all coho and Chinook salmon greater than 55 mm in fork length. Fish were released to the site of capture. Surveys were conducted using a submersible antenna and reader on 4 occasions in each stream until late September, and again the following spring to locate tagged fish. Sampling was conducted in late September to recapture tagged fish. Site fidelity was determined as the portion of tagged fish that remained within the stream reach in which they originated. Growth rates were determined by the change in weight and length of recaptured fish over time. Chinook and coho salmon were tagged in the upland stream, but only coho salmon were captured and tagged in the wetland stream. Site fidelity was highest for Chinook salmon followed by coho salmon in the wetland stream and then coho salmon in the upland stream. By the end of September 23% of the tagged Chinook salmon were still present in the upland stream, 7.4% of the coho in the wetland stream, and 5% of the coho in the upland stream. Growth rates were significantly higher in the wetland stream. The average coho salmon growth rate in the wetland stream was 1.39 g/g/d and 0.32 mm/d. Average growth in the upland stream (coho and Chinook salmon) was 0.5 g/g/d and 0.06 mm/d. Two coho salmon were recaptured in the wetland stream the following spring. Winter growth rates for these fish were 0.22 g/g/d and 0.09 mm/d. Wetland streams of the western Susitna River drainage provide quality rearing habitat for juvenile coho salmon. Growth rates in the wetland stream were higher than most other published values.
