The Antillean manatee Trichechus manatus manatus was once widespread from the south-eastern coast of Brazil to Central America and the Caribbean. In Brazil habitat destruction and overhunting severely reduced and fragmented the wild population, restricting extant subpopulations to the north and north-east coast. In response to these threats an ambitious government-led programme was initiated in 1994, with the aim of rehabilitating orphaned manatee calves and releasing them into the southernmost subpopulation. The programme is unique within Brazil, and has invested unprecedented resources in post-release monitoring. So far 30 manatees have been released at three sites, with a high rate of success (> 75%). Time in captivity appears to be a key variable determining post-release success: too long or too short a time in captivity decreasing the probability of survival. We describe the main features of this long-term programme and identify six key lessons learnt: (1) close monitoring, health assessments and rescues can significantly increase the success of releases, (2) combining different monitoring techniques results in high-quality data and reduces tracking costs, (3) long-term studies are needed to effectively evaluate the results, (4) releasing manatees at c. 5 years of age can increase chances of success, (5) soft-release is important to aid acclimatization, and (6) the programme has been effective in raising awareness among the general public, supporting education and fund-raising.

Alive Antillean manatee stranding is one of the main challenges for the conservation of the species in Brazil. In the present study, data on Antillean manatee stranding recorded by the CMA/ICMBio’s Wild Animals Rehabilitation Center from 1987 to 2015 were analyzed. The CMA and the REMANE’s (Northeastern Aquatic Mammal Stranding Network’s) institutions have rescued on average five Antillean manatees per year. Approximately 56% of the animals were alive when rescued, and 43.7% were found dead. The states of Ceará and Rio Grande do Norte have the highest records of stranding, rescue, and assistance of alive calves. Stranding of alive specimens is more frequent during the austral summer, especially in January, February, and March. In the North region, the main threat to the Antillean manatee population seems to be interaction with fishing activities. Studies on the causes of dependent calf stranding in northeast Brazil are urgently needed to promote the development of public policies for the conservation of the species. Brazil’s manatee rehabilitation centers must undergo improvements to better assist stranded calves, which need special care to survive.