Length: 18 – 24m (60 – 80’)
Weight: 50 – 85 tons
Population size in Canada: Atlantic – 3,300 Pacific – no data available
Population size in World: no recent estimates
Conservation status in Canada: Atlantic – Special Concern, Pacific – Threatened (COSEWIC/SARA)
Conservation status in World: Endangered (IUCN)

Classification

Latin Name: Balaenoptera physalus
Other Names: Finback, Finner, Common Rorqual Razorback, Herring whale
Suborder: Mysticete (Baleen Whale)
Family: Balaenopteridae

Field Identification
    • up to 80’ in length
    • large streamlined body
    • two blowholes
    • large splashguard
    • very tall, columnar blow/spout
    • narrower V-shaped head, distinctive ridge in centre
    • asymmetrical head pigmentation: lower right jaw is white & left is dark
    • brownish body with white pattern across back (chevron), particularly on right side behind blowhole
    • belly and bottom of tail are white
    • tall, falcate (curved) dorsal fin
    • baleen on right side is white in front and greyish-black towards back of mouth, baleen on left side all greyish-black, ~70-90 cm in length
    • ventral grooves extend to or beyond navel area
    • dive sequence fairly rapid but blow and dorsal fin are not observed simultaneously
    • rarely shows flukes
    • group size 3-7 (less commonly 1-22), 100+ may gather at good feeding grounds
Description

Large, sleek and fast, the fin whale is the second largest whale in the world, second in size only to the blue whale. Its dorsal fin is pointed or falcate and sits two-thirds back along the body. They have a pointed head, paired nostrils and a broad, flat rostrum which is divided by a ridge that runs from the blowhole to the rostral tip. Their body is dark grey to brownish black above and white below. Fin whales have an asymmetrical head pigmentation; their lower right jaw is white, while the left lower jaw is dark. The reason for this unique pigmentation is unclear. Many individuals have a pale V-shaped chevron across their back, usually on the right side just behind the head. This marking, together with scars and the dorsal fin shape allows researchers to identify individuals.

Life History

Longevity has not been determined precisely, but individuals of up to 80-90 years old are known. In the Northern Hemisphere, males reach sexual maturity when they are between 6-7 years old and approximately 17.5m in length, whereas females are between 7-8 years old and approximately 18.5m in length. Females give birth to a single calf every two to three years in the winter, after a gestation period of 11 to 12 months. The calves, which weigh 1-1.5 tons and measure 6-7m long at birth, are weaned at 6-7 months when they are approximately 11-13 m long.

Distribution

Fin whales are found in the Pacific, Atlantic and Indian Oceans, mainly in temperate to polar waters in both hemispheres (they are less common in the tropics). The population in the Mediterranean Sea is distinct from that of the North Atlantic. Individuals often concentrate in coastal and shelf waters, but they are also found further offshore in deep water. Their migration patterns are not well understood. Some populations may shift north-south and some may move offshore during the winter. Fin whales are common visitors to the coastal waters off the Maritime Provinces and are often sighted in the Gulf of St. Lawrence any time ice is not present.

Diet

Krill and small schooling fish such as herring, capelin and sandlance make up the fin whale’s diet. They often lunge into prey schools with mouths wide open, turning on their side to engulf their prey.

Behaviour

With their streamlined body, fin whales are one of the fastest whales in the world, capable of reaching speeds up to 25 knots. Although they are often seen traveling alone or in small groups, large aggregations can be found on feeding grounds. Fin whales produce loud, low-frequency vocalizations that travel over hundreds of miles. Very little is known about their mating system and no distinct breeding or calving grounds have been found. The dorsal fin appears shortly after the blowholes when the whale surfaces and they rarely raise their flukes when diving.

Population size

Efforts to estimate population size for this species are confounded by its extensive range and the potential confusion with sei whales. The expense associated with large-scale surveys is a significant limiting factor, particularly in the more remote, offshore waters of British Columbia, Newfoundland and Labrador. Estimates made from 1996-2001 in the North Atlantic (Central and Northeastern) were 23,000 – 39,000 (International Whaling Commission).

Threats

Fin whales were much too fast to be caught by early whalers, but with the advent of modern whaling, fin whales were hunted in huge numbers and their population size was severely reduced. While they are now protected internationally as an endangered species, they are threatened by environmental change, such as chemical and noise pollution. The most significant direct threats are ship strikes, entanglement in fishing gear and disturbance from increasing whale watch activity. In the Maritime Provinces, several incidents of fin whales known to have been struck by vessels have been documented. Fin whales may also be negatively affected by ecological interactions with fisheries but these have not been clearly specified or validated. The ways and degrees to which fin whale populations are being affected by climate change are also unknown.

References

COSEWIC report

International Whaling Commission website: http://www.iwcoffice.org/conservation/estimate.htm#table

Martin, Anthony R. and International Team of Experts. 1990. The Illustrated Encyclopedia of Whales and Dolphins. Portland House, New York, NY.

Reeves, P.A., R.R. Reeves, B.S. Stewart, P.J. Clapham, and J.A. Powell. 2002. Guide to the Marine Mammals of the World. Alfred A. Knopf, New York. 527 pp.

Whale and Dolphin Conservation Societry (WDCS) website: http://www.wdcs.org/