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Is it possible to distinguish individual whales as well as we recognize people?

By Liliane Lodi

English edit by Maria Luiza Albieri and Katyanne Shoemaker

Montage by Carla Elliff

Photo-identification has been used to identify Bryde’s whales based on the profile of their dorsal fin, observing the presence of cuts and scars, by means of a technique called photo-identification. The cuts and scars on dorsal fins are unique features. No whale is like another. These marks can be used like our fingerprints or a barcode.

Photograph taken from the water looking back to the shoreline, with a Bryde’s whale breaching the water surface in the middle. In the background there are green hills and many buildings along the beachfront

The common Bryde’s whale is regularly seen in the Southeast region of Brazil (states of Rio de Janeiro and São Paulo) in areas near the shore, especially during spring, summer, and autumn, since this is not a migrating species unlike other whale species. Here we see the characteristic profile of a breaching Bryde’s whale. (Photograph by Liliane Lodi, ©)

For the past 40 years photo-identification has been used to study numerous populations of dolphins and whales worldwide. This is a non-invasive technique, as the animal does not need to be physically captured or marked. You only need good pictures of its dorsal fin, which can be taken from a distance.

Photograph showing the dark-gray dorsal portion of a Bryde’s whale in the center of the image against a gray-blue ocean. In the background, the shoreline is fuzzy from sea mist, but you can see vegetated hills and a few houses along the beachfront

In Brazil, Bryde’s whales have been reported from the state of Rio Grande do Sul to Bahia, with eventual occurrences in the states of Paraíba and Maranhão. This species is found in coastal and oceanic regions. The dark-gray and silvery uniform color of the dorsal part of the animal, combined with its lean body, makes this one of the most beautiful whales. (Photograph by Liliane Lodi, ©)

During inter- and intraspecific interactions, or even as a result of impact with certain human elements (such as fishing nets and boat propellers) and environmental elements (interaction with the bottom), the dorsal fin can undergo alterations resulting in recognizable patterns of permanent cuts and scars over time.

Photograph clearly showing a scarred dorsal fin of a Bryde’s whale, while it breaches the blue water

Cuts and scars, when present on dorsal fins, are never the same. It is like a fingerprint, which allows us to recognize different animals. (Photograph by Liliane Lodi, ©)

The best photograph of each whale (one with the dorsal fin most in focus and perpendicular to the camera, in high resolution) from a given occasion is considered a sighting (capture). As this identified individual is observed on other occasions, it is a resighting (recapture). With this procedure it’s possible to build a photographic catalog of individuals.

Photo-identification studies provide important information that expands the knowledge about whale populations, behaviors, and ecology that can be used to improve conservation strategies. In addition to the work carried out by specialized scientists, public participation can add important information to this type of study as well.

Photograph showing two breaching Bryde’s whales against a gray sea on a cloudy day. Two rocky islands are in the background and the sea is littered with solid waste

Bryde’s whales swimming among marine litter. The main threats to this species includes accidental captures in fishing nets, habitat degradation and loss, pollution (domestic, chemical, and by sound), collision with vessels, and intentional molestation. (Photograph by Liliane Lodi, ©)

As researchers cannot have eyes everywhere, the “Brydes do Brasil Participatory Research Program” was created in December 2017, a partnership between the Whales and Dolphins Project of Rio de Janeiro and WWF-Brazil. The program is open not only to researchers, but also to environmentalists, nature lovers, nautical sports practitioners, and anyone else who wants to participate. It's citizen science training to keep eyes on whales!

Logo of the Brydes do Brasil research program. The image shows a Bryde’s whale in full profile with the lettering “Brydes do Brasil” in tones of dark and light green

Objectives of the Brydes do Brasil Participatory Research Program

  • Mobilize and involve society in participatory scientific research;

  • Create a database of photo-identified Bryde's whales in Brazilian waters, through a concentrated photographic collection;

  • Identify, compare and quantify new occurrences of Bryde's whales identified in the same area;

  • Determine Bryde's whale movements along the Brazilian coast and key areas for the conservation of the species;

  • Gather records for further analysis in order to understand whether the population is decreasing, stabile, or increasing;

  • Raise awareness of the need for conservation of Bryde's whales and the sustainable use of our coastline as their habitat.

How to participate

You don't have to be a scientist or a professional photographer to learn how to properly photograph a Bryde's whale to aid in the individual identification records used to further the conservation of these animals. So, if you want to help with the research on Bryde's whales, become a contributor to the network!

The results obtained by this shared database can make a major difference in the conservation of the species in Brazil!

Obtaining the pictures

Tips for obtaining quality pictures of the dorsal fin, in order to assist in the individual identification of Brazilian Bryde's Whales, can be found on the website.

The submitted photographs will be analyzed and those considered of good quality will be integrated into a database from which the shared catalog is built. The photographer retains all rights over the images submitted.

Those with a keen eye and camera ready will be the most successful photographers!

IBAMA Ordinance No. 117 of December 26, 1996 defines rules to prevent the intentional harassment of cetaceans in Brazilian jurisdictional waters. Always follow whale watching protocol and do not disturb them for photographs.

In addition to the details and guidelines for identifying these giants, the website also has interactive spaces to share photographs, videos, articles, scientific dissemination texts, media news and other relevant information about the species.

Go with this flow: Learn - Participate - Collaborate - Share!


Looking for more information?

- Participatory Research Program Brydes do Brasil (Formats: Mobile, tablet and computers)

- E-mail:

- Facebook: Where are the Whales and Dolphins?

- Instagram: @baleiasegolfinhosdorj

- IBAMA Ordinance No. 117 of December 26, 1996 (In Portuguese)


About Liliane Lodi:

Liliane holds a PhD in Marine Biology and studies cetacean ecology, with emphasis on distribution, habitat use, behavior and conservation. She is the administrator of the Facebook group “Where are the Whales and Dolphins?” and the Participatory Research Program Brydes do Brasil directed to the area of ​​Citizen Science. She coordinates the Whales & Dolphins research project in Rio de Janeiro (Instituto Mar Adentro, WWF-Brasil and Fundação SOS Mata Atlântica).

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