Fin Whale

Fin Whale

  • Scientific name: Balaenoptera physalus
  • Also know as: Razorback Whale, Finback Whale, Common Rorcual
  • Size: Up to 25 metres and 85 tons
  • IUCN Status
    • Global: EN (Endangered)
    • Europe: NT (Near Threatened)
  • Distribution: Found in deeper offshore waters in all of the major seas and oceans of the world.
  • Feeds on: Filter feeds on krill but also eats fish and squid.
  • Description: Very large whale species with a powerful, streamlined body. Tail fluke is large and single dorsal fin is set far back on the body. Colouration is unusual as this species is black to grey on the back and flanks and white/pale underneath with a chevron pattern on the back.

Fin whales are the second largest whale species in the world, reaching 27 metres (88ft) in length – only the blue whale, the largest animal to ever live on planet earth, is bigger. The fin whale is a fast-swimming whale species which has been intensively hunted throughout the 19th and 20th centuries, meaning they are now classed as endangered across much of their range.

Distribution

Fin Whale Range
Fin Whale Range

Fin whales have an extremely wide distribution, being found in all of the major seas and oceans of the world, although are more common in cooler, temperate waters and avoid both the warm tropics and polar regions. Separate populations may exist in the northern and southern hemispheres, with this species being scarce around the warmer waters of the equator. Due to their size, they prefer to live in deeper, offshore water and do not generally come into shallower water or close to land. Although rare in British waters fin whales are most likely to be sighted off the northern coast of Scotland, but they can be occasionally spotted elsewhere around the coasts of Britain and Ireland.

2016 Strandings Across Britain

In 2016 four fin whales have been found stranded on beaches across the UK, including a 13 metre fin whale found on a Norfolk beach in November of that year and 17 metre fin whale found on a Devon beach in September. This follows around thirty sperm whales being found stranded on beaches in Germany, the Netherlands and the UK at the start of the year. It is not known what is causing the disproportionately high number of large whales to become stranded across Europe’s coastline, but the main theory is that malnourishment due to lack of food causes the whales to become exhausted and then become beached. In March 2017 a very large fin whale washed up on the coast of Devon. It is not known how this fin whale died as the carcass was already heavily decomposed when it reached the shore.

Life Cycle

Fin Whale from the air
Fin whale pictured from the air.

Fin whales are thought to make migrations throughout the year and are seen as a highly transient species. While the exact migratory patterns of fin whales are not fully understood it is believed that they move south from the colder northern waters in winter. Fin whales are often sighted in small family groups of around ten whales, although occasionally much larger migratory groups of tens, or even hundreds of fin whales have been observed. Fin whales have been seen in pairs during the breeding season and it is thought that fin whales mate for life. Like most marine mammal species the newly born fin whales are nursed by their mothers in the early part of their life. Young fin whales will remain close to their mother and feed off her milk for the first year or so of their life before leaving to hunt and feed themselves. The lifespan for this species may be up to one hundred years.

Like other whale species fin whales communicate using low-frequency sounds. It is thought that these vocalisations are used for a range of purposes such as locating food, describing surroundings and finding a mate, although this is not fully understood by science.

Other Species/Related Species

Fin whales in the southern and northern hemispheres may be two different species (and those found in the Mediterranean may be a third species). This is an issue which is mostly of interest to marine biologists and scientists and until further taxonomic research is carried out there only a single species of fin whale recognised. A 1998 study by Harvard University found evidence in whale meat tissue samples that blue whale/fin whale hybrids could exist, although this remains a disputed theory and more research is needed into this area before this can be confirmed.

Feeding

Fin Whale Size
Fin whale size comparison with a human.

Fin whales feed mostly by filter feeding, straining large amounts of krill through the baleen bristles in their jaws. They will also eat fish and squid with small schooling fish such as anchovy and herring being taken, although fin whales have also been known to eat much larger fish such as cod, pollock and ling. They are fast swimmers which are able to hit speeds in excess of 20 miles per hour, dive to depths of 500 metres and stay submerged for up to twenty minutes. However, most dives do not reach anywhere close to these depths and last only a few minutes.

Hunting and Conservation Efforts

Commercially Caught Fin Whale
Commercially caught fin whale being processed, Hvalfjörður, Iceland, 1986.

Like most large whale species the fin whale has been hunted intensively over the last few centuries. While the speed of fin whales meant that they were difficult for sail-powered boats to catch the advent of steam-powered vessels meant that fin whales could be caught much more easily. The size of this species made it a valuable catch for whalers with the oil, blubber and meat all fetching high prices. The hunting of fin whales continued into the Twentieth Century, but by the 1970s fin whales had protection from hunting in all of the major oceans around the world.

Fin whale meat on sale.
Icelandic Fin Whale Meat on Sale at Fujimaru Department Store, Obihiro, Japan

However, in 2005 and 2006 Japan and Iceland began commercially hunting fin whales again, taking up to ten fin whales each per year. This has continued intermittently up until the present day with Iceland planning to take up to 180 fin whales a year in 2013. This is thought to be fuelled by the demand for whale meat in Japan, with almost all Icelandic caught fin whale meat being exported there. While the IUCN state: “It seems unlikely that catching of fin whales will return to the high levels of previous years”, the resumption of commercial whaling will obviously reduce the number of this species and prevent numbers from recovering. In addition to this, a number of fin whales are killed every year in both collisions with boats and being caught in commercial fishing nets. The number of fin whales in the wild is unknown, but the species is certainly threatened and fin whales are currently classed as Endangered by the IUCN on a global basis, Near Threatened in Europe and Vulnerable in the Mediterranean.