Response of Guiana dolphins to the construction of a bridge in Ilhéus, Northeastern Brazil.

This study aimed to investigate whether the use of space and movements of Guiana dolphins were altered during the construction of a cable-stayed bridge at the mouth of the Cachoeira River estuary in Ilhéus, Brazil. We described and compared the visitation rate, use of space, and movements of the Guiana dolphins across two periods: before the construction began (2015-2016) and during the construction of the bridge (2017-2020). A theodolite and a total station were used to observe and record the trajectories of the dolphins.