There are approximately 80 described species of cetaceans worldwide, all of which are listed in the IUCN Red List and in CITES Appendix I. Approximately 30 species, including 9 baleen whales and 21 toothed whales and dolphins, are known or thought to occur in coastal and pelagic waters around Madagascar. All of them without distinction are strictly protected under Malagasy fisheries law 93-022.
Among the baleen whales, the Humpback whale (Megaptera novaeangliae) is the most common in Madagascar, visiting the island during fall and winter months. Every year, humpback whales migrate from the Antarctic feeding grounds and begin to arrive off southern Madagascar in May to reproduce in the coastal waters of Madagascar. The last whales leave in December. Madagascar provides breeding and calving habitat for humpback whales throughout its coastal waters, including in the primary WCS seascape regions in Antongil Bay, the Southwest (Anakao to Salary Bay) and the Northwest (Nosy Be region).
The humpback is an important national emblem of marine conservation, the focus of WCS research and conservation efforts since 1996, and a major marine tourism attraction in several locations. Humpback whales in the Indian Ocean were the target of intensive industrial whaling until about 1955 when stocks were severely depleted. Since that time, humpback whales have steadily recovered.
WCS has been monitoring the recovery of humpback whales off Madagascar, assessing population abundance and population interchange with other sub-stocks in the Southwestern Indian Ocean (SWIO) through photographic identification and population genetic techniques. WCS work off Madagascar has been instrumental in the pan-hemispherical assessment of humpback whale populations by the International Whaling Commission, establishing the state of recovery for the SWIO population and relationships with populations through the southern hemisphere. Recent work using satellite telemetry to track individual whales remotely during the breeding season is providing information on how whales use the breeding habitat and move throughout the SWIO. WCS researchers also study the complex breeding songs of humpback whales, to describe how it changes over time and compares with songs of whales in the South Atlantic and Eastern Indian Ocean, clues to movements on an Oceanic scale. Humpback whales seem to have no major threats within the waters of Madagascar. However, marine noise from shipping or seismic surveys could affect their breeding success. Poor regulations on whale watching could have an impact as well.