Report of the Working Group on Interactions between Humans and Tursiops truncatus in the Southwest Atlantic Ocean

Abstract

In this work we compiled the available information about humans and bottlenose dolphin interactions in the Southwest Atlantic Ocean (SWAO), including issues as historical direct takes, incidental captures in fisheries, positive interactions with fisheries, interactions of dolphins with tourism and boat traffic, habitat modification or degradation, and environmental pollution. The data compiled in this review demonstrated that coastal bottlenose dolphins are under anthropogenic pressure in the SWAO. Direct take of bottlenose dolphins in the wild does not appear to be an issue of conservation concern in the SWAO. Although the species is exposed to bioaccumulation of micropollutants, it is suggested that contamination level is lower when compared to bottlenose dolphins from other continents. Coastal works can impact bottlenose dolphin behavior and habitat use in a short-term, but those seem to be reversible when works stop. Bycatch occurs throughout the species distribution and seems to be occasional in Uruguayan and Argentinean waters, where there is evidence of a historic decline in dolphin sightings. In Brazil, bycatch is apparently low in the northeast and southeast coasts, but is frequent in certain areas of southern Brazil. Studies on the subject are scarce or preliminary and a great effort is still required to understand the real impact of human activities on bottlenose dolphins in the SWAO.