A Lagrangian approach to model movement of migratory species

We introduce a Lagrangian movement model that can be used to characterize cyclic migrations of iteroparous fish populations. We demonstrate how movement parameters can be estimated using conventionally available catch-at-age data and provide a description of the potential bias that may arise from model misspecification, data aggregation, and nonstandardized sampling effort. The model can be extended to incorporate covariates representing biological and environmental forces that alter the distribution and migration range of exploited populations. We expect that this movement model will be a useful tool to model fish migration, to illustrate how fisheries dynamics are affected by fish migration, and to be used as an operating model in closed loop simulations to test the robustness of management frameworks to spatial structure and connectivity.