Actualités

One of the major collaborative achievements of IndoCet over the past decade has been the development of a regional humpback whale photo-identification programme across the Western Indian Ocean. Researchers from multiple countries have progressively pooled their datasets through the Happywhale platform, enabling large-scale comparisons of humpback whale movements and connectivity between breeding areas. The preliminary results of the regional comparison have been presented a the IWC Scientific committee (Paper SC/70/PH/04) this year.

This initiative contributes to the IWC Southern Ocean Research Partnership (SORP) and efforts to better understand exchanges between Breeding Stocks B and C and adjacent Southern Hemisphere populations. Since the first uploads in 2018, the number of encounters available on the platform has increased dramatically, reaching more than 14,000 encounters representing over 8,000 identified individuals from data collected between 1988 and 2025. Contributions now include datasets from South Africa, Mozambique, Tanzania, Kenya, Madagascar, Réunion, Mauritius and Mayotte, while citizen science photographs are also increasingly incorporated.

Analyses of these data have already revealed more than 160 matches between regions of Breeding Stock C, demonstrating important movements and long-term connectivity between eastern Africa and the south-west Indian Ocean islands. Some individuals have been resighted over periods exceeding 25 years, highlighting a tendency for some whales to show strong site fidelity combined with broad regional movements. This dataset and further collaboration are expected to play major roles in the development of abundance estimates in future as well as connectivity analyses, and the upcoming IWC Southern Hemisphere humpback whale assessment. 

IndoCet will develop an export tool to facilitate data management by researchers, and tools to provide annual updates on the IndoCet website and progress reports. 

Contributor : Violaine Dulau