Sightings of humpback whales on the Vitória-Trindade chain and around Trindade Island, Brazil

Abstract

The Trindade and Martim Vaz islands belong to an archipelago located 1,140 km east of Vitoria, Espirito Santo State, Brazil, in the Southern Atlantic Ocean. The archipelago consists of six islands of which Trindade (20°30’S and 29°18’W), with an area of 10.1 km², is the largest and Martim Vaz, with an area of 0.3 km², the second in size. The archipelago has a total area of 10.4 km² (4.0 sq mi). Its isolation on the ocean surface makes it difficult to perceive that it is part of the Vitoria-Trindade Alignment, a great E-W submarine volcanic chain. The volcano lies on the ocean floor at a depth of about 5,500 m. Other volcanic constructions belonging to this alignment between Trindade-Martim Vaz and the coast have been completely eroded by the sea, and leveled down to 100 m depth. They are the guyots, usually called banks, but the islands, probably due to prolonged volcanic activity, are still high above the ocean surface. The Trindade island platform has a limited area, the width varying between 800 and 3,000 m (ALMEIDA, 2002). In the Southwest Atlantic Ocean the winter breeding ground of M. novaeangliae is located on the north-eastern coast of Brazil, on the Abrolhos Bank (16°55’S, 38°50’W) and in its surroundings (ZERBINI et al., 2004). The Abrolhos Bank, with its shallow (0-50 m), warm waters (23