In order to study the ecology, behaviour and life history parameters of a specific population of a certain species, it is necessary to identify the individuals that belong to that population. The identification of individuals allows us to understand a little better certain parameters, such as the size of the population, their migratory routes, residence, site fidelity, life spans and their social structure. Most cetaceans have natural marks such as individual contours of fins or flukes, nicks and notches on them, colouration patterns, scars and deformities that can be used for individual identification. Photo-identification is based on this principle and involves photographing a part of the body that can be considered unique to that animal for later comparison. These parts of the body used for identification vary according to the species, the dorsal fin being used for dolphins, for example, and the fluke for sperm or humpbacked whales. Photo-identification is a non-invasive, low-cost technique, when compared with other methods, such as tagging.

In this project, the photo-identification surveys are mainly concentrated along the south coast of Madeira, although survey trips to the Desertas and Porto Santo are planned. During the systematic nautical surveys, whenever one of the target species is sighted, photo-identification of the individuals will also be made.