Use of Artificially Propagated Pacific Lamprey Entosphenus tridentatus to “Supplement” Supplementation Research and Species Recovery

Pacific lamprey, an important subsistence, ceremonial, and medicinal food source for Columbia River Basin (CRB) tribes, is a prehistoric anadromous fish species from the Pacific Coast of North America and Asia. To prevent further decline and local extirpations, the CRB tribes and a consortium of partnering agencies began developing artificial propagation and early rearing techniques for Pacific lamprey in 2012. Work to date has focused on developing the best methods and techniques associated with egg fertilization, incubation, and rearing of larvae. The transition from prolarvae to first-feeding larvae appears to be a survival bottleneck of early life stages in hatchery settings.  There is enough knowledge in the Pacific Northwest region to begin a supplementation program to reintroduce and supplement locally extinct and functionally extinct populations.  New monitoring associated with supplementation programs, in concert with ongoing hatchery research, will likely reveal other new discoveries about the early life history of lamprey, such as critical food resources, feeding strategies, survival and growth rates, optimal density levels, environmental sex determination, demographics, and migration behavior.  Genetic typing of both hatchery-reared and wild larvae holds great promise for assigning parentage, examining mating systems, and identifying genetic traits that have allowed lamprey to persist for millennia.