A Spatial Capture – Recapture Model to Estimate Fish Survival and Migration Patterns from Linear Telemetry Arrays

Advances in telemetry technology, including smaller transmitters and stationary receivers, allow studies to collect a plethora of spatial data on tagged individuals.  While computing capabilities and software (e.g., GIS) offer options to analyze spatial data, quantitative models capable of using all data points are lacking.  We developed a spatial capture-recapture model to evaluate survival and movement of migratory fishes in a North Carolina river and present an American shad Alosa sapidissima example.  Using a resistance board weir near the river mouth, we tagged individuals with passive integrated transponders (PIT) in the spring of 2010.  An array of upstream PIT antennas passively recaptured individuals during upstream and downstream migrations.  The river channel constrained migrations, resulting in linear and one-dimensional data.  Using a Bayesian framework in OpenBugs software, our spatially explicit version of the Cormack-Jolly-Seber model incorporated all antenna recaptures and accounted for migration patterns across time periods for each individual.  Outputs include survival and activity center (i.e., location) estimates with associated uncertainty (i.e., credible intervals) at each time period.  This spatial capture-recapture model is applicable for any linear array (e.g., rivers, lake shorelines, coastal routes), opening new opportunities to study demographic parameters and patterns in movement or migration and habitat use.