Clackamas River Bull Trout Reintroduction Project: Monitoring bull trout with census redd counts and PIT tag technology, 2011-2016. Starcevich, S. Technical Report 2016.
Clackamas River Bull Trout Reintroduction Project: Monitoring bull trout with census redd counts and PIT tag technology, 2011-2016 [pdf]Paper  Clackamas River Bull Trout Reintroduction Project: Monitoring bull trout with census redd counts and PIT tag technology, 2011-2016 [link]Website  abstract   bibtex   
Bull trout were extirpated from the Clackamas River basin by the 1960s. A reintroduction feasibility assessment and an implementation plan were completed in 2007 and 2011, respectively, with the goal of establishing a self-sustaining population of 300-500 adults in the Clackamas River basin. Phase one of the project (2011-2016) involved translocating 2,868 bull trout (80% as age-1 and 2) from the Metolius River basin, tagging each with a passive integrated transponder (PIT tag), releasing them in the upper Clackamas River basin, and monitoring them using a variety of methods. Monitoring methods included census redd counts and detection of PIT-tagged bull trout at a PIT detection site in Pinhead Creek. The number of redds observed and adult PIT-tagged bull trout (defined as age-5 and older) detected have steadily increased from 18 redds and 15 adults in 2013 to 68 redds and 72 adults in 2016. There was a strong linear relationship between the annual redd count and the number of adults detected in Pinhead Creek, suggesting that redd counts may be useful in tracking trend in adult abundance. In 2016, adults detected in Pinhead Creek were translocated mainly at age-1 and 2 (i.e., 70-210 mm), released at locations both in Pinhead Creek and the Clackamas River, and spent a median of 26 d in Pinhead Creek during the spawning period. The second phase of the project begins in 2017 and entails continued monitoring of progress toward the reintroduction goal, at least in part through census redd surveys and the use of PIT tag technology, of producing naturally-reproducing, self-sustaining population of bull trout in the Clackamas River basin.

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