Distribution and Behavior of Adult Pacific Lamprey (Entosphenus tridentatus) Translocated into Tributaries of the Snake and Clearwater Rivers, ID

Decades of decline in Pacific Lamprey (Entosphenus tridentatus) within the Columbia River Basin have increased attention on regional restoration efforts as well as highlighted the need for basic ecological and life history information. Pacific Lampreys are culturally important to the Nez Perce Tribe, who have been translocating adults into local spawning streams in an effort to restore populations. These efforts provided an opportunity to obtain important biological information for lamprey within an interior spawning stream as well as qualitatively evaluate translocation protocols, movement patterns and spawning behavior of adult lamprey, and subsequent larval recruitment as relative measures of translocation success. Within the initial study (2006-2008), the movement patterns, spawning activity, and habitat selection of individual adults were monitored in tributaries of the Snake River using radiotelemetry. Subsequent monitoring of larval recruitment and juvenile outmigration in translocation streams coupled with genetic analysis at all life history stages, has provided further information (2008-2015). Results suggest that translocation may be an effective tool in lamprey restoration. In addition, increased knowledge of adult spawning behavior may help guide rangewide lamprey restoration efforts.