In a devastating environmental crisis, the lifeless bodies of 120 Amazon river dolphins have been discovered floating in a tributary of the Amazon River in Brazil over the past week. The Mamiraua Institute, a research group at Brazil’s Ministry of Science, Technology, and Innovation, reported two additional dolphin casualties on Monday in the Tefe Lake region.
Experts point to severe drought and scorching temperatures as likely culprits, with the Tefe Lake region experiencing temperatures exceeding 39°C (102°F) in the past week. The distressing discovery extends beyond dolphins, as thousands of fish have also succumbed to the harsh conditions, according to local media.
Miriam Marmontel, a researcher at the Mamiraua Institute, expressed concern about the impact on the unique Amazon river dolphins, known for their striking pink colour. Approximately 80% of the carcasses found belong to this pink dolphin species, locally known as “boto,” potentially representing a significant blow to their estimated population in Lake Tefe.
Marmontel highlighted the vulnerability of these dolphins due to slow reproductive cycles, emphasising that a 10% loss could pose a serious threat to the species’ survival in Lake Tefe. Both the boto and the grey river dolphin, known as the “tucuxi,” are listed as threatened species on the International Union for Conservation of Nature’s red list.
Responding to the crisis, Brazil’s Chico Mendes Institute for Biodiversity Conservation has mobilised veterinarians and aquatic mammal experts to rescue any surviving dolphins in the lake. While the cause of the spike in dolphin mortality is not definitively established, scientists are exploring potential factors such as bacterial infections.
The alarming rise in water temperatures, reaching 39°C, coincided with the emergence of at least 70 carcasses last week. Although the water temperature briefly decreased, it surged again to 37°C on Sunday, heightening concerns among experts.
Environmental activists attribute the unusual heat conditions to climate change, exacerbating droughts and heatwaves. Ayan Fleischmann, the geospatial coordinator at the Mamiraua Institute, emphasised the broader impact on Amazonian communities, leaving them isolated without access to essential resources like quality water and transportation.
Nicson Marreira, mayor of Tefe, spoke of the challenges faced by his city of 60,000 residents, unable to deliver food to isolated communities due to dry riverbeds.
