Habitat use of Guiana dolphins (Sotalia guianensis) in the Ararapira Channel, Cananeia Estuarine-lagoon complex, São Paulo State

Abstract

The study of habitat use is concerned to the definition of key areas and important biological and social centers and is central to the understanding of species ecology. Therefore, this paper aims to analyze the distribution, through the study of habitat use for the Guiana dolphins, Sotalia guianensis, in the Ararapira Channel, Cananeia Estuarine Complex, São Paulo State. The observations will be made through a platform of opportunity (Valongo), and the survey track and group sighting points will be recorded by a GPS. Physical parameters (co-variables) such as water surface and air temperature, salinity, turbidity, depth, tide and sea state, cloud cover, wind direction and focus, will all be collected every 20 minutes. The behavior of sighted dolphins will also be evaluated, as well as their number and distance in relation to the channel margin. For a better definition of the methodology used at this work, a pilot study was previously conducted in the area. The analysis will be done through the computer package "adehabitat" running from the free software R. The resulting maps will be displayed in the ArcGIS, allowing a better interpretation of the use of this area by this dolphin species.