Fin Whale

Description

The fin whale is the second-largest animal on Earth, exceeded in size only by the blue whale. Adults typically reach lengths of 65 to 80 feet and weigh between 40 and 80 tons. Fin whales are characterized by their sleek, streamlined body with a distinctive asymmetrical coloration on the lower jaw: the right side is white while the left side is dark gray or black. This unique pigmentation pattern is unlike any other cetacean species and may play a role in feeding strategy. Their dorsal fin is prominent, curved, and set far back on the body, rising at a shallow angle from the back. The body is dark brownish-gray on the dorsal surface with a lighter underside, and they often display light-colored chevron patterns behind the head. Their blow is tall and narrow, reaching up to 20 feet in height.

Habitat & Range

Fin whales inhabit all major oceans of the world, from polar to tropical waters, though they are most commonly found in temperate and cool waters. In the eastern North Pacific, they range from the Gulf of Alaska to Baja California, with significant numbers observed in the waters off Southern California throughout much of the year. Unlike some baleen whales, fin whales do not follow a strictly defined migration route, and some populations may remain in productive feeding areas year-round. The deep waters of the Southern California Bight, including areas offshore from Orange County, provide important foraging habitat. They tend to prefer deeper offshore waters compared to coastal species like the gray whale, though they can occasionally be spotted from shore during periods of high coastal productivity.

Diet

Fin whales are versatile filter feeders with a diet that includes krill, small schooling fish such as anchovies, sardines, and herring, as well as squid. They employ a lunge-feeding technique, accelerating toward prey aggregations and engulfing massive quantities of water and prey in a single gulp. An adult fin whale can consume between 1.5 and 2 tons of food per day. The asymmetrical jaw coloration may serve a functional purpose in feeding, with the white right lower jaw potentially being used to startle or corral schooling fish. Fin whales have between 260 and 480 baleen plates on each side of the upper jaw, which are used to strain prey from the water. They often feed cooperatively, swimming in coordinated patterns to concentrate prey before lunging.

Behavior

Fin whales are among the fastest of the great whales, capable of sustained speeds of 23 miles per hour and bursts up to 29 miles per hour, earning them the nickname “greyhound of the sea.” They are typically found alone or in small groups of two to seven individuals, though larger aggregations of up to 100 or more may form in productive feeding areas. Fin whales can dive to depths of around 250 meters and typically remain submerged for 5 to 15 minutes. Their vocalizations are low-frequency pulses, typically around 20 Hz, that can travel vast distances across ocean basins. These calls are among the most powerful biological sounds produced by any animal. Fin whales have a lifespan estimated at 80 to 90 years, and females produce a single calf every two to three years after a gestation period of approximately 11 to 12 months.

Conservation Status

Fin whales are classified as Vulnerable on the IUCN Red List and remain listed as Endangered under the U.S. Endangered Species Act. Intensive commercial whaling in the 19th and 20th centuries killed an estimated 725,000 fin whales in the Southern Hemisphere alone, dramatically reducing global populations. Since the moratorium on commercial whaling by the International Whaling Commission in 1986, some populations have begun to recover. The northeastern Pacific population is estimated at several thousand individuals. Primary ongoing threats include ship strikes, which are a leading cause of mortality in some areas, as well as entanglement in fishing gear, underwater noise pollution, and the effects of climate change on prey availability. In the busy shipping lanes off Southern California, vessel speed reduction programs have been implemented to help reduce the risk of fatal collisions.