Teng-Wei Lin

Title: Forecasting the trajectories of Southern Resident Killer Whales with stochastic continuous-time movement models
Date: Wednesday, November 29th, 2023
Time: 9:00AM
Location: Hybrid, over zoom and in LIB 7200
Supervised by: Dr. Ruth Joy

Abstract:

The Southern Resident Killer Whale (SRKW) is an endangered species present in the Salish Sea. This fish-eating predator is impacted by human activities, particularly commercial vessel operations. Forecasting the trajectories of SRKWs helps provide early warning alerts to slow down or reroute commercial vessels, and reduce the risks of ships overlapping with whale presence. In this study, we develop a stochastic animal movement model that is guided by a historical database of sighting records of SRKWs. Specifically, we make use of a continuous-time Ornstein-Uhlenbeck (O-U) velocity process that provides the basis for a movement forecast system and simulates realizations of SRKW velocities and trajectories given initial conditions. However, if the forecast system were to simply rely on the O-U velocity process alone, it would steer simulated whale trajectories to areas where SRKWs are rarely found. To address this, we propose a direction blending scheme to project the simulated velocities in more realistic directions. It makes use of historical directional information along with the O-U velocity process to create more probable pathways consistent with observed SRKW movement patterns. By integrating the simulated trajectories generated from the simulated velocities, we establish a preliminary dynamic probability-based forecast scheme that demonstrates skill in forecasting SRKWs trajectories on time-scale of hours.