Dead Whales in Puerto Madryn: What We Know and How Our Volunteers Are Helping
What is happening in Puerto Madryn and Península Valdés
In recent weeks, southern right whales have been found dead along the coast of Puerto Madryn and Península Valdés, in Chubut, Patagonia. Local media report that seven whales were found in less than a week, in addition to dead calves reported earlier in the season. Figures vary by source and are provisional. Scientists are still studying the causes. Our Whale and Puma Conservation volunteers, based near Puerto Madryn, have been in the field supporting the local reserve team.
Southern right whales (Eubalaena australis) travel to the sheltered gulfs of northern Patagonia every year to mate, give birth and raise their calves. The season runs through the spring, and the area is one of the most important refuges for the species in the world.
Earlier in the 2026 season, authorities reported dozens of dead calves along the Valdés coast. More recently, adult and juvenile whales began appearing on the beaches of Puerto Madryn, which scientists are now studying. Local residents have also asked for public information about the situation.
It is important to keep some perspective. Authorities have pointed out that right whales die every year and that mortality varies a lot from one season to another. Even so, the speed and the change in the profile of the animals are what caught the attention of researchers.
What scientists are investigating
The investigation separates two situations. In the calves, early analyses detected a bacterium called Erysipelothrix rhusiopathiae, which can cause severe systemic infection. So far, there is no evidence of a human-caused factor.
The adult whales are being studied under a different hypothesis. According to local reports, the recently found adults were in good nutritional condition and had plenty of food in their stomachs. That is compatible, as a preliminary idea, with exposure to natural toxins produced by harmful algal blooms, commonly known as red tide. This has not been confirmed, and laboratory results are still pending. Tissue samples were sent to the national fisheries research institute (INIDEP) and stomach contents to the Universidad Nacional de la Patagonia San Juan Bosco.
The work is coordinated by the Southern Right Whale Health Monitoring Program, led by Dr. Marcela Uhart of UC Davis, with the participation of researchers from institutions such as CONICET and its Patagonian research center, CENPAT, located in Puerto Madryn.
For context, in 2022 around 30 whales died in Golfo Nuevo over a few weeks, and the Instituto de Conservación de Ballenas attributed that event to red tide toxins. Each episode is different, so no conclusion about the current one should be drawn until results are available. Information is changing quickly: for updates, rely on the official communications of the institutions involved.
Where our volunteers fit in
Mondify’s Whale and Puma Conservation program is based near Puerto Madryn, in Patagonia. Volunteers in the program work alongside local conservation teams, and during this situation they joined the reserve staff in the field.
In the photos, volunteers can be seen measuring one of the animals and documenting the site with photographs, supporting the reserve team. This kind of basic information (size, condition, location, photographic records) is part of how scientists build a clear picture of an event like this one.
To be clear: the scientific analysis and the search for causes are led by the specialized institutions mentioned above. Volunteers support the fieldwork, they do not replace the experts. Taking part means learning from the local team and contributing to data collection.
Why this matters
Southern right whales were hunted to near extinction and have been recovering for decades. Monitoring programs like the one in Península Valdés are what allow us to detect problems early and respond with evidence. Every extra pair of trained hands in the field helps the people doing that work.
If you want to be part of conservation work in Patagonia, you can learn more about our Whale and Puma Conservation program.
