A food chain-based ecological risk assessment model for oil spills in the Arctic environment

Highlights: • Cascading effects of oil spill on the food web of the Arctic marine apex predators is quantified. • Role of sea ice, weather and physiology of organisms is used to estimate the ecological risk. • Bayesian Network based model is developed to estimate risk to adult and offspring of the apex predators. • Risk to marine organisms is assessed based on various spill scenarios in ice infested waters. • Season of spill and location of spill hold significance in assessing impact to food web. This paper investigates the linkage between the acute impacts on apex marine mammals with polar cod responses to an oil spill. It proposes a Bayesian network-based model to link these direct and indirect effects on the apex marine mammals. The model predicts a recruitment collapse (for the scenarios considered), causing a higher risk of mortality of polar bears, beluga whales, and Narwhals in the Arctic region. Whales (adult and calves) were predicted to be at higher risk when the spill was under thick ice, while adult polar bears were at higher risk when the spill occurred on thin ice. A spill over the thick ice caused the least risk to whale and adult polar bears. The spill's timing and location have a significant impact on the animals in the Arctic region due to its unique sea ice dynamics, simple food web, and short periods of food abundance.