Sightings of sei whales (Balaenoptera borealis) in Pacific Canadian waters from systematic surveys conducted in 2018-2021
Systematic distance sampling surveys were conducted in offshore waters of the Canadian Exclusive Economic Zone in 2018, 2019 and 2021. This report contains preliminary results on sightings of sei whales made during those surveys: 4 groups (5 individuals) were observed in 2018 and 37 groups (93 individuals) were observed in 2021 while no sei whales were sighted in 2019. A large, dispersed aggregation of 25-30 sei whales was observed during the 2021 survey and skin samples were collected from two individuals. Most sightings in 2018 and 2021 were made in an area characterized by the presence of large seamounts. Differences across years are reminiscent of observations from whalers that sei whales could abruptly appear or disappear from certain areas. Next steps will include abundance and density analyses, consideration of environmental covariates, and genetic analyses of skin samples.