Análise do uso de hábitat de tartarugas marinhas nos Estados do Pará e Maranhão.

Abstract

Sea turtles are reptiles belonging to the superfamily Chelonioidea and are represented by seven species worldwide, five of which are found along the entire Brazilian coast. Despite their wide distribution, their reproductive cycles, migrations, habitat use, and spatial behavior differ, and significant gaps still exist regarding the effects of the environment on sea turtle movements. In this context, the aim of this study is to investigate the spatial distribution and habitat use patterns of four sea turtle species - Chelonia mydas, Eretmochelys imbricata, Caretta caretta, and Lepidochelys olivacea - in the coastal region of the states of Pará and Maranhão, using satellite telemetry data. The data were obtained from the literature, corresponding to the latitudes and longitudes where the tagged specimens traveled. These data were subjected to kernel density analysis to estimate the home range of the species, using the 95th and 50th percentiles as criteria for the radius, where the 95th percentile represents the distribution area of the individuals and the 50th percentile represents the areas of greatest use. Subsequently, intersections and overlaps of the kernels were calculated to verify shared habitats. The occurrence points were used to extract values for the following environmental variables: sea surface temperature, distance from the coast, depth, current speed, and were subjected to variance analyses to verify specific variations between the habitats traveled by each species. The occurrence points and environmental variables were subjected to multidimensional Mantel and Procrustes correlation analysis to test the level of correlation and explanatory percentage of this set of variables on animal movements. The analyses were performed in Rstudio software. The home range estimates identified important hotspot areas for the individuals, possibly associated with feeding and nesting. Overlap calculations indicated shared areas that could potentially be ecological corridors. Habitat use analyses highlighted that Caretta caretta exhibits significant variations in the routes traveled compared to the others. The multidimensional correlation demonstrated that the variables used have good explanatory power regarding the animals' movements.