Discover what are fin whales doing in São Miguel

fin whales study biologists futurismo
Follow Maria’s journey to discover what are fin whales doing in the south of
São Miguel, Azores

Hi! I am Maria Ernesto, a Marine Biology Master student at the University of Algarve that joined Futurismo to prepare a master thesis researching fin whales off São Miguel! Join me as we welcome you on board Futurismo Azores Adventures and explore the wonderful world of fin whales!

Here in Futurismo we love showing you the beautiful Atlantic Ocean surrounding the Azores, and we take every opportunity at sea to feed our curiosity and discover new things about our beloved cetaceans!

The fin whales belong to the Cetacea suborder Mysticeti, or baleen whales, and are a member of the Balaenopteridae family, the rorqual whales, whales with pleated throat grooves. This family includes species such as blue whale, sei whale, Bryde’swhale, minke whale and the humpback whale, which can all be sighted here in the Azores.

Fin whales are the second-largest species on Earth ranging from 17 to 27 m length and between 30.4 to 81.2 tons. Female adults are typically bigger than males and individuals from the southern hemisphere are usually larger. Its body coloration is mostly dark grey with a white ventral region, the asymmetrical head pigmentation with pale grey chevron and white lower jaw on the right side and a darker grey on theleft side are unique characteristics of this species.

Figure 1 and 2. Dark grey lower jaw on the left side (figure on the left) and white lower jaw on the right side (figure
on the right).

The fin whales diet is composed of little crustaceans commonly named krill, and small schooling fish such as capelin, herring, or blue whiting. Their pleated throat grooves allow them to expand their mouth and consequently to ingest big quantities of food at once!

They can be found in all the world’s major oceans and some seas, and some have been recorded pursuing long seasonal migrations from warm tropical breeding grounds where they stay in winter to the feeding grounds in cold polar waters where they enjoy the summer. During these journeys, fin whales cross the Azores every year in spring where we can see them and say hello! However, we do not know exactly where they are coming from and where they are going, so we decided to use all the photographs taken during our trips in Futurismo to try to identify the whales. This method is called photo identification, we use the photographs from the dorsal fin and different marks and scars spread on their bodies to recognise special features on each whale and create a catalogue with all the photographs for every whale identified by the Futurismo team! Later we compare the photographs taken in São Miguel to other photographs taken in different places of the Atlantic and try to see if there are matches!

After checking all the photographs from the last 11 years we were able to identify 261 fin whales! And we found out that, like our visitors, some whales like to comeback to São Miguel and revisit the Futurismo boats and crew. We have 32 re-sightings!

Some are months or even years apart (Figure 3 and 4)!

Figure 3. Re-sighting between years. Photographs from Futurismo. Fin Whale Catalogue: left side of Bp75 first sighted in April 2014 and in May 2016 (right side).
Figure 4. Re-sighting between seasons. Photographs from Futurismo Fin Whale Catalogue: right side of Bp21 sighted twice in May 2014 (1/5/2014 and 3/05/2014) – expected northward migration (left side) and in November 2014 – expected southward migration (right side).

We also confirmed, as we expected, that fin whales prefer the Azores during spring but sometimes they like to pass by in other times of the year (Figure 5).

Figure 5. Temporal distribution of fin whales around São Miguel between 2009 and 2019 (year/number of sightings:
2009/32; 2010/34; 2011/15; 2012/42; 2013/104; 2014/183; 2015/93; 2016/155; 2017/116; 2018/121; 2019/10).

As you can see, some have been sighted together with other big whale species, as well smaller species such as dolphins, birds or fish (Figure 6).

Also, behaviours such as diving, socializing and foraging were recorded (Figure 7).

We hope we can continue this work and find out more about this emblematic whale. The fin whales are considered a “vulnerable” species and they need our help to continue to live happily and without human threats! Join us at Futurismo and help protect our oceans!!! Check out this poster presented by Maria last December in the XIX National Ecology Encounter, Portugal. And if you want to know more about our work with fin whales, don’t hesitate to check out the posters presented by Laura González García (et al., 2014) at the international meeting on Marine Research (IMMR, Peniche, Portugal 2014) or by Clara Sardà (et al., 2013) and Victor Ojeda (et al., 2018) at the European Cetacean Society Conference(ECS Setúbal, Portugal 2013 or La Spezia, Italy 2018 respectively).

Written by Maria Ernesto


Aguilar, A., & García-Vernet, R. (2018). Fin Whale. Encyclopedia of Marine Mammals, 368–371.

Boyd, I. L., Bowen, W. D., & Iverson, S. J. (2010). Marine mammal ecology and conservation: a handbook of techniques. 450.

Gonzalez Garcia, L., & Torres Palenzuela, J. M. (2019). Cetacean distribution in São Miguel (Azores): influence of environmental variables at different spatial and temporal scales.

Valente, R., Correia, A. M., Gil, Á., González García, L., & Sousa-Pinto, I. (2019).Baleen whales in Macaronesia: occurrence patterns revealed through a bibliographic review. Mammal Review, 49(2), 129–151.

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