Fin whales are the second largest mammal on the planet (only the blue whale is larger). They feed on euphausiids (a shrimp-like crustacean), herring, capelin, other shoaling fish, and squid! Like other baleen whales, the fin whale strains its food from the water through baleen plates.
Overview
The fin whale is the second largest baleen whale on earth and the second largest animal ever. Only blue whales exceed them in size. Adults reach approximately 25m (80 – 85 ft) in length, with females growing 5-10% larger than males. Fin whales, the “greyhound of the sea”, possess a streamlined, grey body with a dorsal fin located approximately three-quarters of the way down their back that measures up to 60cm high, which is large relative to its body length compared to other rorqual whales and therefore serves as its namesake. Fin whales are especially distinguishable by their asymmetrical pigmentation along their lower jaw: dark grey on its left, light cream on its right. Upon birth, a fin whale calf is usually about 6 meters (20 ft) in length, and is then weaned at 6-7 months of age. At an average of 6-8 years of age, fin whales reach sexual maturity, and physical maturity at approximately 25 years.
Fin whales occur worldwide, in every ocean, and are largely viewed as an offshore, oceanic species. They are most commonly found within subpolar and temperate regions in deep offshore waters over the continental slope (with notable exceptions, including the whales in this catalog). Habitat preferences appear driven by the confluence of oceanographic processes and physiographic features, such as submarine canyons and troughs, which enhance the supply and concentration of prey in productive regions of the ocean.
It had long been assumed that fin whales migrate between summer foraging grounds at high latitudes and winter breeding grounds at lower latitudes, like most other baleen whales. However, migrations are now thought to be more complex and region-specific. Some populations even remain sedentary year-round, like certain populations along the Canadian coastline and in the Southern California Bight, USA, while others probably perform seasonal long-range migrations.
Fin whales occur on BC’s continental shelf year-round, and the migratory movements of Canadian Pacific fin whales remain unknown. The presence of fin whales in BC waters during the fall and winter suggests that this area is used for mating and calving, as male whale song intensifies (associated with mating) and peak calving time aligns with those months as well.
The area has been highlighted as an important area for fin whales and likely represents unique nearshore fin whale habitat on the Pacific Coast of Canada. Their return raises questions about the current and past importance of such fjords to species that have typically been considered offshore. As their populations continue to recover, we will determine to what extent they may come to rely on this habitat and understand the potential importance of these whales to the ecological function of the north coast.
Very little is known about the social life of fin whales. What is known is inferred largely from their vocalizations, particularly their songs, which are defined as patterned, 20-40 Hz call sequences that last up to several hours in duration. Limited evidence has associated this song with male fin whales performing mating displays, and songs are heard mainly during the fall, with some activity in winter and little in the spring and summer. Scientists have documented geographic differences in song structure in the Atlantic Ocean with a song structure varying both seasonally and inter-annually. There are complex patterns in song variation documented throughout the Pacific Ocean, but they do not reveal clear geographic population differences, except for in the Gulf of California and off the coast of British Columbia.
The Kitimat Fjord System (KFS), in the traditional waters of the Gitga’at First Nation as well as other coastal First Nations, was the only Canadian-Pacific fjord system where fin whales were commonly found and killed during commercial whaling. Whaling records document that fin whales were completely removed from these waters by 1967, and they were not recorded here again until 2006, shortly after our research in the region began. What started as just 3 unique fin whales seen in 2006 has grown to over 100 individuals documented in our research area by 2025. Worldwide, this is the only fjord system where fin whales are known to occur regularly with the same individuals returning year after year – something that is potentially globally unique to this region.
As with other fin whale populations elsewhere in the world, the primary threats to BC’s fin whales are noise pollution, ship strikes, entanglement in fishing gear, and climate-related changes to prey supply and distribution:
