Results from our 8th season

Despite challenging conditions and a continued decline in whale shark sightings, the team carried out an intensive field season focused on research, conservation, and local engagement.

Scientific research expanded in exciting new directions in 2025. Aboard Ad Astra, we continued gathering valuable data through photo-identification, movement tracking, and prey research. At the same time, we contributed to ongoing genetic and pollution studies to deepen our understanding of connectivity across the Indian Ocean and the environmental pressures shaping marine life. We welcomed three students from marine biology institutions in Madagascar, who focused their fieldwork component on the anthropogenic impacts of tourism on whale sharks in Nosy Be and the spatio-temporal distribution of plankton in surrounding waters.

With 20 active receiver stations now in place thanks to collaborations with other researchers in the region, we deployed acoustic tags when possible. Preliminary analysis of the acoustic data from August 2025 showed that whale sharks use the Nosy Be area throughout the year, often at night or offshore where they are rarely observed. This highlights just how important the region remains for the species, even as surface sightings fluctuate. We are busy writing up a paper on our results so far.

Our data also played a key role in conservation action. This year finally saw the official creation of a new Key Biodiversity Area in northwestern Madagascar, and the review of the national decree governing protected species — with whale sharks, rays, sea turtles, and marine mammals proposed for full legal protection for the first time. We continued to support the development of the country’s first marine corridor — a major step toward long-term protection for whale sharks and other threatened marine species.

Tourism management remained a key focus in 2025 as whale shark tourism continued to grow in Nosy Be. Alongside local partners, we helped launch the Nosy Be Ocean Collective — a new network bringing together tourism operators, associations, and stakeholders to promote more responsible marine tourism through shared commitments, improved coordination, and concrete conservation actions. We also piloted the Ocean Ambassadors program, training local scientists and educators to engage directly with tourists through interactive events, raising awareness about marine biodiversity and best practices around wildlife encounters. Together, these initiatives aim to create safer experiences for both people and wildlife while building long-term, community-led stewardship of the ocean.

The 2025 Season in Numbers

• 84 boat surveys
• 67 whale shark encounters
• 39 individual sharks identified
• 9 new sharks added in 2025
• 546 total sharks identified since 2015
• 79% male individuals
• 20 active acoustic receiver stations
• 42 plankton samples collected
• 10 baitfish samples collected

Despite the challenges of declining sightings and increasing tourism pressure, the season was a productive and inspiring one. By nurturing local talent, standing alongside communities, and building lasting conservation partnerships, we are shaping a future where science, nature, and people thrive together.

None of this work would be possible without the generous support of our donors and the dedication of our many local and international partners — thank you for helping make whale shark conservation in Madagascar a reality.

Spoiler alert: An exciting match in another Indian Ocean country was recently confirmed, and will be revealed soon through a new scientific publication. More news soon!