Qualitative risk assessment of impact of Toxoplasma gondii on health of beluga whales, Delphinapterus leucas, from the Eastern Beaufort Sea, Northwest Territories

Abstract

In recent years, the protozoan parasite Toxoplasma gondii has increasingly been recognized in Arctic fauna, including beluga whales (Delphinapterus leucas) in the Eastern Beaufort Sea (EBS), Northwest Territories. We qualitatively assessed the risks of T. gondii to the health of EBS beluga because of their importance in livelihood of Arctic communities as well as their potential role as sentinels. This risk assessment used a standard framework including hazard identification, hazard characterization, exposure assessment, and risk characterization. We conclude that currently, the EBS beluga are at moderate risk of exposure to T. gondii, and low risk of developing disease associated with toxoplasmosis, based on the small amount of data available (only healthy, hunter-harvested animals have been examined). Although there was a high level of uncertainty due to limited published data and the challenges in determining prevalence and significance of disease in wild marine mammal populations, overall the EBS population was currently considered to be at a low risk for population level impacts of toxoplasmosis. Finally, we identify knowledge gaps that can guide future research, provide better evidence for future risk assessments, and ultimately better detect and mitigate changing risks for health of Arctic beluga, as well as the communities that rely on sustainable, healthy populations for harvest.

Keywords

• qualitative risk assessment
• toxoplasma gondii
• beluga whales
• delphinapterus leucas
• beaufort sea