In the realm of the Fin whales
by firmm Team
Text: Brigitte, photos: firmm
When we were finally able to head out to sea again at the end of May, after nine days without any trips due to strong Levante winds, we were treated to numerous sightings of Fin whales. What people usually know about Fin whales is that they are huge. Our marine biologist, José, asked one of our young passengers on board how big a Fin whale is. The child proudly replied that they grow to 100 metres in length. Well, they aren’t quite that big, but at around 25 metres, they’re still a quarter of that length.
Another young visitor claimed, during the information session before the trip, that female whales are bigger than the males. Is that true? You’ll find the answer below.
Over the course of about 10 days, we were treated to nine sightings. The whales were always swimming westwards, which is typical for this time of year.
Fin whale sightings 30.05.-08.06.
- 30th of May at 14:35, 5 Fin whales
- 31st of May at 12:30, 4 Fin whales
- 31st of May at 12:30, 4 Fin whales
- 1st of June at 12:25, 3 Fin whales
- 1st of June at 13:45, 3 Fin whales and at 14:15, 1 Fin whale
- 3rd of June at 12:50, 1 Fin whale
- 4th of June at 11:20, 2 Fin whales + 2 calves
- 4th of June at 14:40, 2 Fin whales, breaching
- 8th of June at 12:15, 1 Fin whale
6 facts you probably don’t know about Fin whales:
So the little boy was right. And this is actually the case for all six species of baleen whales. This characteristic is known as reverse sexual dimorphism and is linked to the extreme biological demands associated with reproduction, lactation and migration. A larger female can build up more fat reserves.
Fin whales are among the fastest of the large whales. Because of their speed and their slender, streamlined bodies, they are also known as the «greyhounds of the seas». In short sprints, they can reach speeds of up to around 47 km/h.
The front third (or possibly up to half) of the baleens on the right-hand side is very light in colour or white. Towards the back, they are darker in colour. On the left-hand side, however, all the baleens are dark grey. This asymmetry is also evident on the lower jaw: it is white on the right and dark grey on the left. With the tongue and the inside of the mouth, it is the other way round: the left side is light, the right side dark. This is thought to be due to both the capture of prey and camouflage.
In Andalusia, the Fin whale was hunted between around 1920 and 1960 by boats operated by the whaling factory in Getares (Algeciras). Around 5,000 animals were killed during this period. Although whaling has long since ceased, there are other threats to the animals. The status on the IUCN Red List, based on the 2018–2021 assessments, has even been upgraded from ‘Endangered’ to ‘Critically Endangered’ for the Mediterranean subpopulation.
Fin whales can live to a very old age. They can swim through the ocean for up to 100 years. However, significantly older specimens have also been found. Until 2010, a whale aged 116 was considered the oldest of its kind. Then, off the coast of Denmark, an animal was found whose age was estimated at 130–140 years. How can you determine their age? To do this, experts carry out a chemical analysis of the amino acids in the eye lens.
Weighing between 30 and 80 tonnes, the Fin whale needs a great deal of food. To meet this need, it filters up to 2,000 kilograms from the water every day. Any krill and small fish that get caught in its baleen are swallowed down. And, unfortunately, so is the plastic that it ingests unintentionally. This plastic cocktail then often blocks its stomach.
