Sei Whale Atlantic population
Scientific Name: Balaenoptera borealis
Taxonomy Group: Mammals
COSEWIC Range: Atlantic Ocean
COSEWIC Assessment Date and Status Change: May 2019
COSEWIC Status: Endangered
COSEWIC Status Criteria: A2cd
COSEWIC Reason for Designation: This large whale occurs off Nova Scotia, Newfoundland, and Labrador. The population was greatly reduced by whaling that ended in 1972. Systematic surveys of Canadian Atlantic waters in 2007 and 2016 recorded few animals. The current population is likely fewer than 1,000 mature individuals and below its size at the end of whaling. Major current threats include collisions with ships, and underwater noise, especially that associated with shipping and petroleum exploration and production.
COSEWIC History of Status Designation: Species considered in May 2003 and placed in the Data Deficient category. Re-examined in May 2019 and designated Endangered.
SARA Status: No schedule, No Status
Date of Listing (yyyy-mm-dd):
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Sei Whales (Balaenoptera borealis) are large baleen whales with an average size of about 15 m in length and 19 tonnes for adults, although they can reach lengths of over 19 m. This baleen whale species has a tall and curved dorsal fin, and is generally dark grey or bluish-grey with a lighter whitish underside. Sei Whales may have circular, white or grey scars on their sides and underside. They look very similar to Fin Whales, but the right side of their lower jaw is dark in coloration (whereas the lower right jaw in Fin Whales is white). Sei Whales also have throat grooves/pleats that are shorter than some other baleen whales, including Fin Whales. This species can live up to 60 years of age. Sei Whales reach sexual maturity between the ages of 5 and 15 years and have a gestation period of approximately 10 to 12 months.
Sei Whales inhabit pelagic waters in all oceans, most frequently temperate waters, and generally make seasonal migrations from low latitudes in the winter to higher latitudes in the summer. In Atlantic Canada, they have been observed off Newfoundland, on the Scotian Shelf and Slope, and in the Labrador Sea in the summer, with some Sei Whales found in these waters year round. There have also been some observations in the Gulf of St. Lawrence. The locations of Sei Whales’ wintering grounds and breeding grounds are unknown. Sei Whales’ preferred feeding habitat is pelagic waters with high concentrations of zooplankton, especially copepods. Sei Whales will also feed on fish such as Capelin and Herring, and are then seen in shallower waters close to the coast of southern Newfoundland.
Sei Whales can swim at speeds greater than 55 km/hour and are considered one of the fastest marine mammals.
Current threats to Sei Whales include noise from manmade sources, ship strikes, and entanglement in fishing gear. Historically, their population size was greatly reduced due to whaling that began in the late 1800s and ended in 1972 in eastern Canada.
Provincial and Territorial Protection
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
6 record(s) found.
- COSEWIC Status Reports (2 record(s) found.)
- Response Statements (2 record(s) found.)
- Permits and Related Agreements (2 record(s) found.)
COSEWIC Status Reports
Response Statements - Sei Whale (2004-04-21)A response statement is a communications document that identifies how the Minister of the Environment intends to respond to the assessment of a wildlife species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The document provides a start to the listing and recovery process for those species identified as being at risk, and provides timelines for action to the extent possible.