Updates on sei whale (Balaenoptera borealis) distribution, abundance estimates, and acoustic occurrence in the western North Atlantic
Danielle Cholewiak, Debra Palka, Samuel Chavez-Rosales, Genevieve Davis, Elizabeth Josephson, Sofie Van Parijs, Sarah Weiss
International Whaling Commission
Due to expanded visual and passive acoustic survey monitoring effort off the US east coast in recent years, more information is becoming available on the distribution and occurrence of sei whales in the western North Atlantic. Two separate efforts to generate habitat-based density models based on visual survey data are producing seasonal abundance estimates for the â€˜Nova Scotiaâ€™ stock, ranging from Nova Scotia to the southeastern US. Both methods predict high density in spring and summer months along the Georges Bank region and Scotian shelf. The winter distribution and migratory behavior of sei whales in the western North Atlantic continue to be poorly understood. The acoustic monitoring off Georges Bank has documented what appears to be persistent presence of animals at two sites throughout fall, winter and spring. However, acoustic monitoring in southeastern US waters is also revealing the wintertime presence of at least some animals in the Blake Plateau region, providing preliminary evidence of winter migratory movements.