Tagsim: Software to Provide Spatial Transition Matrices from Electronic Tag Data

We present an R package for deriving population-level movements from electronic tag data and deriving seasonal transition matrices between spatial strata. Simulations apply an individual based advection diffusion model and uses parameters derived from movements and positional uncertainty from groups of tagged individuals. We demonstrate the method for deriving, and visualizations of, seasonal transition matrices between spatial zones.  We present sensitivity analyses using the University of Massachusetts Large Pelagics Research Center’s database of Atlantic bluefin tuna (Thunnus thynnus) tagged off the Canadian Maritimes. Movement matrices that are constructed from size-based simulations provide a fishery independent source of information which may be used to inform spatially explicit operating models and stock assessments. Utilization distributions from simulations may be further used towards fishery vulnerability assessments.