Potential interactions between small boats and marine turtle aggregation zones in Isla Arena, Campeche

Abstract

Within the Gulf of Mexico, five of the seven species of sea turtles are distributed and carry out important stages of their life cycle. The marine habitats of sea turtles are subject to various threats, including bycatch and boat traffic. The objective of this research was to identify in the marine portion of Isla Arena, Campeche, sites of use of space for its feeding, internesting, and migration stages, as well as zones of potential interaction with small vessels distributed in the study area. For this, satellite tracking of three species of post-nesting female sea turtles, Eretmochelys imbricata, Lepidochelys kempii and Chelonia mydas, were used, with which the home range was estimated and through a grid of the study area made up of 170 hexagons of 21 km2 area, the sites of intensity of space use were estimated for each stage. With this information and with the quantification of vessels identified in the marine area of Isla Arena from January 2017 to December 2019 through Sentinel-2 satellite images, the areas of greatest interaction in three different seasons were identified. As a result, the sites with the highest use of space in the feeding stage are the south and north of Isla Arena, while for internesting the line parallel to the coast is where the highest use occurred; for migration, most of the study area has a use that goes from high to regular. Regarding the potential interaction with boats, for feeding season one (January to April) was the one that presented the greatest interaction in the north and south of Isla Arena, while the west and north represent the areas of highest interaction for migration during season three (September to December), and season two (May to August) for internesting. The results of this research highlight that tourist activity represents another important stressor for important aggregation zones for sea turtle populations.

Keywords: Turtles, interaction, vessels, track, marine.