Modeling Study Analyzes Sperm Whale Recovery after Environmental Disturbances
Researchers (Azmy S. Ackleh (dean), Ross A. Chiquet (math), Baoling Ma (math), Tingting Tang (math), Hal Caswell, Amy Veprauskas (math), and Natalia Sidorovskaia (physics)) used population models to investigate how reduced survival and fertility after environmental disturbances, such as an oil spill, might affect sperm whale populations. Model simulations indicated that the magnitude of a disturbance had a stronger impact on recovery from lethal and sublethal effects than its duration. When comparing lethal and sublethal effects of the same duration, reduced survival influenced a population’s probability of recovery more than reduced fertility, even when reproduction stopped completely for the full duration of a disturbance. The researchers published their findings in Ecotoxicology: Analysis of lethal and sublethal impacts of environmental disasters on sperm whales using stochastic modeling.
Photo: Dean Ackleh reviews modelling simulations of how environmental disturbances impact sperm whales. The contour plot on the left shows that a small change in survival rates over a long time period results in a large change in population dynamics. (Photo provided by A. Ackleh.)