HuDoNet at IndoCet in Kenya

IndoCet - Indian Ocean Cetacean Consortium’s - Special Session at WIOMSA

Jambo! Whale- and dolphin biologists gathered in Mombasa, Kenya, at the end of September 2025 for the 13^th Scientific Symposium of WIOMSA (Western Indian Ocean Marine Science Association). This is a unique platform for dialogue, knowledge exchange, and collaboration among researchers, policymakers, and other stakeholders in the region. WIOMSA members hail from five countries along the eastern seaboard of Africa and five islands in the WIO.

On the final day, we had the IndoCet Special Session. The main take-aways? There is amazing work being conducted on cetaceans in the WIO and working together expands our impact exponentially!

Firstly, IndoCet, as the Indian Ocean Cetacean Consortium is known, has been fostering and advancing cetacean research and conservation in the western Indian

Ocean (WIO) since 2014. The consortium was born out of a collaboration that focussed on the satellite tracking of migrating humpback whales in the region and it has expanded to include all cetaceans here. For example, in this session, besides the many talks about humpback whales, there were also pygmy killer whales, false killer whales, actual killer whales, melon-headed whales, sperm whales and more - and obviously we mentioned Indian Ocean humpback dolphins.

Did you know, there are acoustic recorders all over the SWIO? About 50 of them! Numerous whales have been tracked with satellite tags. Thousands of photos of humpback whales have been uploaded to Happywhale, depicting >9000 distinctive individuals

photographed during >11000 encounters in the SWIO. There’s such a thing as Synchronised Whale Counting Day in the region. In 2025, eight countries participated: Kenya, Tanzania, Mozambique, Madagascar, South Africa, Reunion, Mayotte and Mauritius. Together they logged 447 sightings of humpback whales on one day in August.

There’s a regional collaboration amongst Comoros, Madagascar, Mozambique, South Africa and France to understand interactions between fisheries and toothed whales. When predators take fish off of fishers’ hooks – a behaviour called “depredation” – it causes human-wildlife conflict because of economic losses and damage to fishing gear for fishers, and entanglement injuries, bycatch, or retaliatory killing of marine megafauna. This collaboration aims to understand the socio-ecological mechanisms and effects of some of these conflicts to identify sustainable solutions to turn conflict into coexistence. 

One of the most widespread collaborations is a study investigating the diffusion of

humpback whale song. Humpback whale males sing songs which change over time as they adopt and modify the most popular versions of the songs they hear. Globice’s scientists examined acoustic recordings from 17 different places (Marion and Crozet Islands, Namibia, South Africa (western, southern and eastern), Mozambique, Tanzania, Kenya, Mayotte, Madagascar (northwest, northeast, southwest), Reunion, Mauritius and Australia (northwest, southwest). They found an eastward diffusion of songs between years, with a year’s delay,

and complex connectivity within years. 

The Cet’izen Project is another fabulous regional project, including Reunion, Madagascar, Mayotte and Kenya, led by Globice. They are developing educational tools and activities to engage citizens in cetacean science. Their pictures are worth a thousand words. Really professional! 

The Cet'izen Project engages citizens in cetacean science.

We heard what various networks are doing, for example:

• NeMMO (Network of Marine Mammal Observers) leverages ships that are already engaged in other activities to collect marine mammal data;

• Sustainable Whale and dolphin tourism Watching Network of IORA (Indian Ocean Rim Association which

  strengthens regional cooperation and sustainable development across the IO, east and west) is part of a cross-cutting Blue Economy theme;

• Kenya Marine Mammal Network has been conducting marine mammal surveys and working with communities to find solution to bycatch and other issues;

• and HuDoNet has been working towards galvanising conservation action for humpback dolphins.

We learnt about a spatial “network” of IMMAs - Important Marine Mammal Areas - that have been identified based on biological attributes of marine mammal species, e.g. their vulnerability, different life cycle stages, etc. This is a useful place-based conservation tool that has been wielded in the WIO and has potential for further use.

There were more projects showcased than can be mentioned – whale disentanglement capacity building, training for strandings, fascinating projects modelling between-year variability in humpback whale occurrence, innumerable humpback whales in super-groups, and more.

© Dave Hurwitz - Simon’s Town Boat Company

Yet there are as many, if not more, threats to our cetaceans and everybody agreed we need a regional action plan for research-based conservation and mitigation of threats - one that is simple and readily updateable, perhaps modelled on the regional status report on sharks and rays. This is something we as IndoCet will begin to tackle, collectively. We have witnessed the power of radical collaboration.

Asante sana! Thank you very much to the IndoCet organisers and a special thanks to Globice. Please visit IndoCet.org and Globice.org.