Coastal dolphins and other large marine vertebrates were assessed in the Nosy Iranja and Ampasindava peninsula region (Ankivonjy MPA) and in the waters of Nosy Be during November and December 2012 by the WCS Ocean Giants team. During the 36-day expedition, 132 hours of surveys were conducted in Ankivonjy MPA and 118 hours around Nosy Be. Ten species of cetaceans were sighted in 58 groups during the surveys (nine species in Ankivonjy alone).
Among the Mysticetes (large baleen whales) we documented the presence of three species. Most notably we sighted a pair of blues whales in deep offshore waters, which represents the best documented observation of this endangered species. In the waters be- tween Nosy Be and the Ampasindava peninsula, Bryde’s whales were sighted on multiple occa- sions, providing new information on a rare and poorly understood baleen whale in Madagascar. There were three humpback whale groups sighted, all mother-calf pairs, which is noteworthy since it was particularly late in the breeding season.
Among Odontocetes (toothed whales and dolphins), Indo-Pacific humpback and Indo-Pacific bottlenose dolphins, short-finned pilot whales, offshore Common bottlenose dolphins, spinner dolphins, spotted dolphins and a very rare observation of a group of beaked whales (likely Cuvier’s) were also observed in Ankivonjy. Abundance of some of these species was noteworthy with mixed-species groups of spinner and spotted dolphins in excess of 500 and on at least one occasion greater than 1000 individuals.
These preliminary survey results suggest that Ankivonjy MPA and surrounding waters, encompassing shallow coastal, shelf break and deep-water habitats, has particularly high species diversity and supports a large cetacean community. This information is important especially because this region is also a place where oil exploration activities are ongoing and exploitation is planned and would likely have detrimental effects on the marine biodiversity.