This year has been quite different for everyone, and it wasn’t an exception for Futurismo. Due to the covid-19 pandemic, we were not able to have as many encounters with the most charismatic species of our oceans as we would like to. However, as always, Azores biodiversity surprised us in several of our whale watching trips. One of these amazing surprises was the re-sighting of our resident Risso’s dolphin family, on the morning of November 9th. They haven’t been seen since 2019!
In our team of marine biologists, we have one member who is truly passionate about Risso’s dolphins (Grampus griseus). Rafael Martins, marine biologist and whale watching skipper at Futurismo Azores Adventures, focuses his master’s thesis research on creating the first photo identification catalogue of Risso’s dolphins in the island of São Miguel.
Risso’s dolphins are born with a dark colour and as they age, they acquire scars and marks on their bodies, becoming almost completely white when they are old. These scars are marked until the end of their life and the marks on the dorsal fin are a key element for the identification of different individuals.
In order to identify them, Rafa developed a specific photo-identification application which allows him to codify each single dorsal fin according to the different marks. After the classification of each fin, the information is uploaded into a database that does a search, thus selecting the possible fins that correspond to the classified one, and therefore saving a lot of work and time.
For this study, 11,260 photos of Risso’s dolphins taken from whale watching trips have been collected since 2010. From those photos, 569 Risso’s dolphins have been identified, of which about 12 are recorded regularly every year since 2010. This so-called “resident family” is a nursery group composed of 8 adult females and 4 juveniles. As they are relatively few in number, Rafa knows the different dorsal fins of all these individuals! Therefore, he is able to identify this famous family as soon as he sights them on board our whale watching vessels, even though certain individuals acquire new scars, as you can see in the two photos of Ind.97, also known as “A”. You can also check out the photos of our well known “Star”!
Risso’s dolphin ind.97 also known as “A”
Ind.97 (November 9th, 2020) Ind.97 (catalogue photo)
Risso’s dolphin ind.97 also known as “STAR”
Ind.88 (November 9th, 2020) Ind.88 (catalogue photo)
Find out more about Futurismo and their great work here: www.futurismo.pt