Patterns of larval Pacific Lamprey occupancy and abundance suggest that certain natal areas are more productive than other areas.  What is less clear is whether these productive natal areas act as sources for returning adults.  Identifying natal areas that contribute to adult Pacific Lamprey production (and identifying characteristics of those areas) will help guide conservation efforts such as passage and restoration in the Pacific Northwest.

Isotopic signatures in eye lenses have the potential to define natal origins of Pacific Lamprey.  As eye lenses develop in an individual, they store elements from surrounding water; thus, isotopic composition of the core and early layers relate to the chemical composition of water at the individual’s natal region. The chemical composition of river water is a function of underlying geology and land use. To identify natal origin from microchemistry in eye lenses, isotopic signatures must be stable and different among natal areas. SMCM will assess eye lenses to determine natal origins of pacific lamprey.