On the evening of July 11 or early in the morning of July 12, 1997, a group of six rough-toothed dolphins (Steno bredanensis), consisting of five adults and one juvenile, live-stranded in a mangrove swamp near the mouth of the Cairuçu River, in Mamanguá Gulf (Figure 1). The stranding site is located in Ilha Grande Bay, south of Rio de Janeiro State, on the southeastern coast of Brazil. The stranding site was remote and news of the event took more than a week to reach the office of Projeto Golfinhos (Dolphins Project), whose research team did not interview members of the rescue team until July 24.