Assessment of the first decade (1994-2004) of west indian manatee´ reintroduction (trichechus manatus) program in the northeastern coast of Brazil

Abstract

Thirteen captive manatees were released and tagged in three different northeastern coastal areas as part of the Brazilian Manatee Reintroduction Program from October 1994 to December 2004. All individuals were monitored locally with VHF transmitters and four were also tracked with satellite tags for different lengths of time. Manatees were tracked from Praia do Forte, Bahia state (12.538ºS/38.474ºW) to Macau, Rio Grande do Norte state (5.084ºS/36.682ºW) along 1200 coastal km of the northeast six states. To evaluate the re-adaptation process was the main objectives of this work, which will hopefully help researchers to make decisions in the future. Two release areas (RA) were beaches with shallow waters, seagrass beds, reefs and close to small rivers; and one was located inside a large estuary with few seagrass beds. Captivity time was not considered in this evaluation but can be an important factor on the success of the manatee reintroduction program. Five manatees occupied home ranges and each contained sites of high fidelity where they spent considerable time. Two manatees were re-captured shortly after release, having moved long distances, including offshore movements into deep waters. Six manatees had few tracked time. Although manatees had few age when released they have found natural conditions for them survival including reproductive behavior. The fidelity sites choose to release manatees in terms of environmental was very similar. A discontinuous occurrence area (RA2) has been used by some released manatees where a first released manatee female had her calf. We strongly recommend: Continuous of this Manatee Reintroduction Program, to protect this three released areas, develop studies in fidelity sites and one new release area in Ceara coast.