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Pre-spawning migration of adult Pacific lamprey, Entosphenus tridentatus, in the Willamette River, Oregon, U.S.A.

June 5, 2012

We describe the migration distances and timing of the adult Pacific lamprey, Entosphenus tridentatus, in the Willamette River Basin (Oregon, U.S.A.). We conducted aerial surveys to track radio-tagged fish upstream of a major waterfall and hydropower complex en route to spawning areas. We detected 24 out of the 43 fish that passed the waterfall-hydropower complex. Of the detected fish, 17 were detected multiple times. Their maximum migration distance upstream in the mainstem Willamette approximated a normal distribution. The maximum distance migrated upstream did not significantly correlate with total body length (r = −0.186, P = 0.385) or date that the fish passed Willamette Falls (r = −0.118, P = 0.582). Fish migrated primarily during the spring to early summer period before stopping during the summer, when peak river temperatures (≥20°C). However, at least three fish continued to migrate upstream after September. Behavior ranged from relatively slow migration, followed by holding; to rapid migration, followed by slow migration further up in the basin. This study provides a basis for informing more detailed research on Pacific lamprey in the future.


Citation Information

Publication Year 2012
Title Pre-spawning migration of adult Pacific lamprey, <i>Entosphenus tridentatus</i>, in the Willamette River, Oregon, U.S.A.
DOI 10.1007/s10641-011-9910-3
Authors Benjamin J. Clemens, Matthew G. Mesa, Robert J. Magie, Douglas A. Young, Carl B. Schreck
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Biology of Fishes
Series Number
Index ID 70004020
Record Source USGS Publications Warehouse
USGS Organization Cooperative Research Unit Seattle

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