Ana Carolina Meirelles
Other projects
28 Jan 2009
Distribution and Conservation of the Antillean Manatee (Trichechus manatus) in North Eastern Brazil
The aim is to obtain the minimum number of manatees that inhabit the estuary and identify and correlate environmental variables and threats that most influence the distribution of the species.
The Antillean manatee is classified as critically endangered in Brazil with an estimated population less than 500 individuals throughout the Brazilian coast and already extinct in Espírito Santo, Bahia and Sergipe States. The estuary formed by the rivers Timonha/Ubatuba, between the coast of Piauí and Ceará States, is large and healthy and there exists one of the Antillean manatee populations most conserved and not well known of Brazil.
The use of side scan sonar will determine the areas of occurrence of manatees and possibly the number of animals that inhabit the estuary, answering questions about abundance estimation, density and living area. Also will be determined areas with higher incidence of manatees, and identified and measured environmental variables that influence the temporal and spatial distribution of the animals, providing data about the habitat use and preference. Through bioacoustics techniques the repertoire of the manatees will be described, recording the sound emitted by the animals and identifying the existence of individual vocal signatures. The anthropogenic threats will be identified and characterized and the quality of the estuary will be monitored by the analysis of toxicity and heavy metals in sediment and water samples collected.
The study of this manatee population, focusing on population dynamics, ecology and anthropogenic threats research are listed as priority actions for the National Action Plan for the Conservation of the Sirenians in Brazil.