Habitat use of dusky dolphin, Lagenorhynchus obscurus, in summer and fall, in Golfo Nuevo, Argentina

GRISELDA V. GARAFFO; SILVANA L. DANS; SUSANA N. PEDRAZA; ENRIQUE A. CRESPO; MARIANA DEGRATI

MARINE BIOLOGY

SPRINGER

Año: 2007 vol. 152 p. 165 - 177

0025-3162

Off Patagonian coasts, Argentina, the dusky dolphin is one of the most common small cetaceans. This species is the aim of newly developed watching activities during summer in Golfo Nuevo. However, the real occurrence and movement pattern are unknown. The objectives of this work were to investigate the predictability of dusky dolphin distribution, group structure and behaviour in the western portion of Golfo Nuevo, with respect to environmental features (bottom depth, bottom slope, distance from shore and substrate). Random transects in the bay were searched by small boat during the summer and autumn of 2001–2004. When a group of dolphins was sighted, estimates of group size, composition (mothers with calves, adults and juveniles only, and mixed groups) and the predominant activity