Different research methods are employed to contribute to the scientific knowledge on franciscanas.
Knowing the number of individuals living in a given location and the trends of this population is essential for conservation. From this information, we can monitor the impacts and the effectiveness of conservation strategies.
One of the main methodologies used by the project is Distance Sampling, which is the sampling of distances in linear transects. It can be performed from vessels or aircraft. All sighted animals are counted and, through statistical methods, it is possible to estimate the density and abundance of a population. Due to the challenge of observing franciscanas in the sea, the project has also been investing efforts in the development of acoustic methods in order to obtain population density and abundance.
Photo-identification is a method that allows recognizing individuals in nature based on their physical characteristics. For most cetaceans, including franciscanas, we use marks acquired on the dorsal fin. In Babitonga Bay, photo-identification has been used in the study of franciscanas since 2011 and allowed the construction of a catalog with more than 30 resident individuals. The method makes it possible to study the life history of individuals, their residence patterns, and estimate the size of the population through statistical mark-recapture methods.
Genetics is also an important tool in the study of populations. Small pieces of skin or muscle from animals found dead are analyzed to verify the degree of kinship and connectivity between populations. Through genetics, Toninhas do Brasil, in partnership with MAQUA/UERJ, evidenced that the franciscanas of Babitonga Bay form a unique population, distinct from those that live on the adjacent coast.
Two researchers at Toninhas do Brasil holding cameras while monitoring the porpoises in Babitonga Bay.