**The title, authors, and abstract for this completion report are provided below. For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**
Recruitment variation in Great Lakes sea lamprey populations - measurement and management implications.
H.A. Dawson1 and M.L. Jones1
1Michigan State University, East Lansing, MI, USA
This completion report documents the findings of three components of a study to investigate recruitment dynamics in Great Lakes sea lamprey populations. The components are each reported in the form of preliminary manuscripts and collectively address all five objectives listed in the original proposal. The first component (stockrecruitment analysis) focused on the recruitment dynamics of sea lamprey across the Great Lakes basin and addressed the objectives of establishing long-term study streams to control sea lamprey spawner abundance and measure recruitment over time (objective # 1), and to explore the interaction between density, movement, growth and recruitment of larval lamprey (objective # 5). The second component (aging analysis) concerned an examination of the use of statoliths and length-frequency distributions for aging larval sea lamprey and addressed the objectives of creating “known-age” populations of larval sea lamprey for validation of age determination using statoliths (objective # 2), and developing age-assignment methods using statistical models that combine lengthfrequency data with partial age composition data (objective # 3). Finally, the third component (modeling) evaluated sea lamprey management strategies that varied in the degree of reliance on alternative control tactics that aim to reduce sea lamprey reproductive success. We developed a spatially discrete model of the Lake Michigan watershed that included a stochastic stock-recruitment relationship (objective # 4) and that explicitly incorporated uncertainty in the larval assessment process that is used to determine streams to target for lampricide control. We used the model to compare the performance of strategies that used differing allocations of control resources between lampricide and alternative control.