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. This paper contains supplementary material that can be found online at
This study represents the first survey of the parasitic fauna of cetaceans off the northeastern coast of Brazil. Parasites were collected from 82 animals rescued from the states of Ceará to Bahia, including the archipelago of Fernando de Noronha. A total of 14 species of cetaceans were evaluated: Sotalia guianensis, Stenella sp., Stenella clymene, Stenella longirostris, Stenella coeruleoalba, Stenella frontalis, Megaptera novaeangliae, Peponocephala electra, Steno bredanensis, Kogia breviceps, Kogia sima, Globicephala macrorhynchus, Tursiops truncatus, Physeter macrocephalus and Lagenodelphis hosei. The parasites were fixed and preserved in 70% ethanol or alcohol-formalin-acetic acid solution (AFA), clarified in phenol and mounted on slides for morphological identification. In total, 11 species and 8 genera of endo- and ectoparasites were identified: Halocercus brasiliensis, Halocercus kleinenbergi, Stenurus globicephalae, Halocercus sp., Anisakis sp., Crassicauda sp. (Nematoda), Phyllobothrium delphini, Monorygma grimaldii, Scolex pleuronectis, Strobicephalus triangularis, Tetrabothrius forsteri, Tetrabothrius sp., Trigonocotyle sp., Diphyllobothrium sp. (Cestoda), Campula sp. (Trematoda), Bolbosoma sp. (Acanthocephala), Cyamus boopis, Syncyamus pseudorcae and Xenobalanus globicipitis (Crustacea). The identification of some species represented novel records for the country and increased the occurrence of some parasites to new hosts. The use of standardized methodologies for collecting and evaluating a larger number of animals is essential for a better understanding of host-parasite relationships in cetaceans and their use as biological indicators in the region.
This study describes the pathologic findings of 24 humpback whales (Megaptera novaeangliae) found stranded along the Brazilian coast from 2004 to 2016. Eighteen (75%) animals evaluated were found stranded alive. From these, 13 died naturally on shore and five were euthanized. Six died at sea and were washed ashore. Of the 24, 19 (79.2%) were calves, four (16.7%) were juveniles, and one (4.2%) was an adult. The most probable cause of stranding and/or death (CSD) was determined in 23/24 (95.8%) individuals. In calves, CSD included neonatal respiratory distress (13/19; 68.4%), infectious disease (septicemia, omphaloarteritis and urachocystitis; 3/19; 15.8%), trauma of unknown origin (2/19; 10.5%), and vehicular trauma (vessel strike; 1/19; 5.3%). In juveniles and adult individuals, CSD was: emaciation (2/5; 40%), sunlight-thermal burn shock (1/5; 20%); and discospondylitis (1/5; 20%). In one juvenile, the CSD was undetermined (1/5; 20%). This study integrates novel findings and published case reports to delineate the pathology of a South-western Atlantic population of humpback whales. This foundation will aid in the assessment of the population health and establish a baseline for development of conservation policies.
Infections by Cryptosporidium spp. in aquatic mammals is a major concern due to the possibility of the waterborne transmission of oocysts. The aim of the present study was to report the occurrence of Cryptosporidium spp. in Antillean manatees (Trichechus manatus) and Amazonian manatees (Trichechus inunguis) from Brazil. Fecal samples were collected and processed using Kinyoun's method. Positive samples were also submitted to the direct immunofluorescence test. The results revealed the presence of Cryptosporidium spp. oocysts in 12.5% (17/136) of the material obtained from the Antillean manatees and in 4.3% (05/115) of the samples from the Amazonian manatees. Cryptosporidium spp. infection was more prevalent in captive animals than in free-ranging specimens.
We estimated the abundance of Antillean manatees (Trichechus manatus manatus) through a large-scale project conducted in 2010 in north-eastern Brazil and evaluated the efficacy of an aerial survey for conservation purposes. Two observers conducted the survey via flights that maintained an altitude of 150 m and an air speed of 140 km h−1, covering over 2590.2 km2 of the coastline. Strip transects were flown in a zigzag pattern. A total of 67 manatees (on- and off-effort) were recorded in 55 sightings. Historical published records of occurrence were formally incorporated using a Bayesian approach. We estimated the manatee population for north-eastern Brazil in the form of a posterior distribution with a mean of 1104 individuals and a 95% posterior probability interval ranging from 485 to 2221 individuals, which indicates high uncertainty. More large-scale studies in the region are warranted to understand temporal trends, in addition to further studies in hotspot areas, with smaller spatial scales, to reduce the coefficient of variation and to allow the use of improved techniques for monitoring the manatees. A greater emphasis on species-specific characteristics and methods to enhance detection probability (e.g. dual observers) are also recommended. The conditions prevailing along the study area were not conducive to aerial surveillance; thus, the results are not a precise estimate of the manatee population. However, these highlight the importance of conservation efforts for the Antillean manatee, considered the most endangered aquatic mammal in Brazil.
ResumoOs peixes-boi marinhos são considerados herbívoros oportunistas, consumindo uma grande variedade de itens alimentares. Objetivou-se com este trabalho identificar os itens alimentares constituintes da dieta dos peixes-boi marinhos em vida livre, na região Nordeste do Brasil. Para tanto foram coletadas amostras de conteúdo estomacal, provenientes de seis carcaças de peixes-boi marinhos, além de amostras fecais de 11 animais nativos e cinco espécimes reintroduzidos. O material foi identificado ao nível de gênero e/ou espécie, através de aspectos morfo-anatômicos, sendo identificadas 21 espécies entre macroalgas, fanerógamas e cnidários. Através destas análises, foi possível observar que os peixes-boi marinhos alimentaram-se de uma grande diversidade de plantas aquáticas, com predominância das algas vermelhas.Unitermos: mamíferos aquáticos, sirênios, macroalgas, fanerógamas, alimentação AbstractIdentification of alimentary components of Antillean manatee diet in the Northeast of Brazil. The manatees are considered to be opportunist herbivors, consuming a great amount of alimentary items. The aim of the present study was to identify the alimentary components of the diet of Antillean manatees in free life in the northeastern region of Brazil. Samples of stomach contents from six Antillean manatee carcasses were collected, in addition to fecal samples from 11 native manatees and five that had been released. The material was identified at the genus and/or species level, based on its morpho-anatomic aspects, and 21 species of seaweeds, phanerogams and cnidarians were presented. Through these analyses it was possible to observe that Antillean manatees fed on a great variety of aquatic plants, with the predominance of red seaweeds.
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