In recent years, the recovery of global humpback whale (Megaptera novaeangliae) populations has been highlighted as one of the greatest successes in conservation biology (BEJDER et al., 2016; NOAA, 2016). A cosmopolitan and migratory species (CLAPHAM; MEAD, 1999), the humpback has benefited from international treaties which, since 1986, have banned hunting worldwide, which almost drove it to extinction between the 19th and 20th centuries. With the elimination of this threat, humpback populations have been growing in various regions of the planet (ANDRIOLO et al., 2010; BORTOLOTTO et al., 2016b; IUCN, 2021), resulting in the species being reclassified from Vulnerable to Least Concern on the International Union for Conservation of Nature Red List (REILLY et al., 2008).
In Brazil, humpback whales breed mainly along the central and northeastern coasts of the country, from Rio Grande do Norte to Rio de Janeiro (MARTINS et al., 2001; SICILIANO, 1995; ZERBINI et al., 2004). The Abrolhos Bank, in the south of Bahia and north of Espírito Santo is, however, their main reproductive area (MARTINS et al., 2001; ANDRIOLO et al., 2006). The population that migrates to Brazilian waters during the winter has been estimated at around 6,250 individuals, and in 2005 corresponded to approximately 30% of the pre-commercial hunting population size (ANDRIOLO et al., 2010; ZERBINI et al., 2011b). A genetic study carried out by Engel and Martin (2009) revealed that the Brazilian population of humpback whales, designated "BSA - Breeding Stock A", feeds in the region of South Georgia Island and South Sandwich, in the Scotia Sea. Telemetry surveys (Zerbini et al., 2006) corroborated this migratory destination after the breeding season in Brazil.
The total protection of this population has allowed humpbacks to reoccupy their original distribution areas along much of the Brazilian coast. In 2014, with the removal of the species from the Official List of Endangered Brazilian Species, the Humpback Whale Project was recognized by the Ministry of the Environment for its fundamental role in the preservation and recovery of the species (INSTITUTO Baleia Jubarte, 2023). Founded in 1988 as part of the initiatives to create the Abrolhos National Marine Park, the project was developed with the aim of studying and protecting the remaining population of humpback whales that reproduce in Brazilian waters, a species that at the time was still threatened with extinction. After more than 35 years of continuous efforts, humpbacks in Brazil have largely recovered. The project, currently managed by the Humpback Whale Institute and sponsored by Petrobras since 1996, maintains five physical bases in Praia do Forte, Caravelas and Itacaré, in Bahia; in Vitória, in Espírito Santo; and in Ilhabela, São Paulo. In addition to these locations, it also operates in other regions through partnerships with similar institutions in the public and private sectors. Its activities are focused on three main areas: research, education and conservation policies, with the aim of ensuring the full recovery of the species
The recent development of tracking technologies, such as the development of the Villum tagging rod (HEIDE-JORGENSEN et al., 2003) and improvements in the construction of transmitters, has allowed for longer monitoring of various species, including the humpback whale. With these advances, it has been possible to track their movements more precisely, revealing that, in addition to their main feeding area in the South Georgia Islands in Antarctica, the species has been sighted in places outside their usual migratory route, such as the coast of Ecuador in the Pacific Ocean and between Mozambique and Madagascar in the Indian Ocean. These sightings suggest that some humpbacks make wider migrations than previously thought.
The revival of humpback whale populations represents not only a triumph for conservation biology, but also a milestone in the balance between human needs and the preservation of biodiversity. The case of humpbacks highlights the importance of global and collaborative protection measures, such as the international hunting ban, and demonstrates the positive impact that scientific efforts, such as the Humpback Whale Project, can have on the recovery of endangered species. In addition, the use of advanced monitoring technologies pushes new boundaries in the study of the species' migrations and habits, revealing patterns that were previously beyond comprehension. This scenario underlines the continued importance of science and environmental management to ensure that, even in the face of new pressures and challenges, the humpback whale's recovery path continues to be an inspiring example of successful conservation and species resilience.
Comments