The Amazonian Aquatic Mammals Laboratory (LMA) of the National Institute of Amazonian Research (Inpa – MCTIC) was created more than four decades ago. Since then it receives pups o
f rescued manatees from poaching and accidental catching in fishing nets. The success of the research, the process of rehabilitation and management of the manatees generated a group of animals able to return to nature. The Reintroduction Program of Amazonian Manatees, was created in 2008 with Ampa’s supporting. In addition to its reintroduction, the Program collects information on the adaptability of captive manatees to the natural environment by studying their daily and seasonal movements, living space and habitat.
The term reintroduction is defined as the “attempt to reestablish a species in part of its original geographic distribution from which it was extirpated, extinct, or declining.” Reintroduction programs are carried out as an alternative to increase the size of populations and promote the preservation of endangered species. In addition to providing opportunities for ecological studies in nature, reintroduced species act as an excellent element for environmental education. Currently, 62 manatees are in the process of reintroduction: 17 animals are being rehabilitated in Inpa, in Manaus, and 25 are in the semi-captivity, in artificial lake in Manacapuru.
Between 2008 and 2009, the first attempts of reintroduction occurred in the Cuieiras river, affluent of the Negro river, with the release of four adult males. These animals showed difficulties in adapting to nature, making it necessary to review the protocol of release and insertion of the previous stage of semi-captivity.
Since 2011, eligible and selected manatees in the INPA captivity are kept for a year in the semi-captive area, in partnership with the private property Fazenda Seringal 25 de Dezembro, located in the municipality of Manacapuru-AM, 70 km away from Manaus. The semi-captive lake has an area of 13 hectares and depth between 1-4 meters, as well as chelonians and numerous species of fish, such as pirarucu and tambaqui. This phase, prior to the definitive reintroduction into nature, favors the gradual adaptation of captive manatees to nature, allowing individuals to acclimatize individuals to the natural conditions of the environment, such as water temperature and turbidity, seasonal variation of river level, natural food and minimize the stereotyped swimming behavior in INPA tanks. At the moment, 25 manatees have been kept and monitored by Ampa in the semi-captivity.
Since 2016, the reintroduction of manatees has been carried out in the Piagaçu-Purus Sustainable Development Reserve, located on the lower Purus River and 223km far from Manaus. To increase the engagement and support of local communities, environmental education activities are carried out with the local communities in the reserve. The selection of the area for the definitive reintroduction of manatees is based on some criteria, such as a record of the species in the region, availability of food, absence or decline of poachingand have the support of communities in the process of protection and monitoring of animals.
The transport of the animals from the semi-captivity to the Piagaçu-Purus Reserve is carried out with a regional boat, with the animals kept in swimming pools with water for a 20-hour journey. Upon arrival, the community members have the opportunity to visit and welcome the animals. Before released, each manatee receives a single-frequency VHF transmitter belt, adapted to the caudal peduncle, weighing 800g. Animals are monitored daily by community members and manatees ex-poachers, who are trained to use radio telemetry equipment .
To date, the inclusion of the semi-captive stage in the protocol presented a 100% success in the survival of post-release individuals. The selection of suitable habitats for the species in the dry and rainy season, the survival of the individuals and the absence of contact with humans are strong indicators of success. Additionally, eight months after release, two animals were recaptured, showing increase in length and body mass. By reason of it is an endemic species of the Amazon, the consolidation of the reintroduction program of manatees represents an important advance in the conservation of the species and its habitat. It is a long-term project, the experiences and results accumulated so far are extremely important to outline the management and conservation guidelines for this species endemic to the Amazon. Throughout 2019 and 2020, it is planned to reintroduce at least 20 manatees from the Amazon into the wild.