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River dolphin die-offs in Amazon droughts

Record Amazon droughts in 2023 and 2024 overheated the shallow lakes used by Amazon river dolphins (boto) and tucuxis, both listed as Endangered by the IUCN.

In September and October 2023, 209 dead river dolphins were collected in Lake Tefé, where water reached 39-41 degrees Celsius in places. In 2024 ICMBio recorded 14 dead aquatic mammals in Tefé and Sea Shepherd counted 37 aquatic mammal carcasses around Coari, including 29 dolphins. As of August 2026 the Mamirauá Institute runs the 'Amazon Sentinel Lakes' monitoring network, and the Geological Survey of Brazil forecasts one of the most severe droughts on record at Manaus in 2026 amid an expected El Niño.

Numbers with sources

Species

Needs

• animal rescue
• veterinary care
• habitat

Who is helping

Organisations that, according to their own publications, work on this event (1). Donations go directly to each organisation's own website - GLOBURNS does not handle payments.

• Mamirauá Sustainable Development Institute (IDSM)
  The Tefé-based Mamirauá Institute carries out research and conservation in the middle Solimões region, including long-term monitoring of Amazon river dolphins and…
  Donate on the organisation's website (mamiraua.org)

Sources

• news.mongabay.com news.mongabay.com/2024/12/the-uncertain-future-of-amazon-river-dolphins-amid-historic-dro…
• news.mongabay.com news.mongabay.com/short-article/2024/09/amazon-lakes-overheat-as-record-drought-drives-do…
• mamiraua.org.br mamiraua.org.br/noticias/emergencia-de-botos/
• revistaamazonia.com.br revistaamazonia.com.br/plano-amazonas-sensores-ribeirinhos-salvar-botos-seca-extrema/
• amazonasatual.com.br amazonasatual.com.br/vazante-do-rio-negro-em-2026-tende-a-ser-a-terceira-mais-severa-da-h…
• liberalamazon.com liberalamazon.com/environment/news/super-el-nino-forecast-raises-fears-of-severe-drought…
• cambridge.org cambridge.org/core/journals/oryx/article/amazon-river-dolphins-inia-geoffrensis-are-on-th…
• riverdolphins.org riverdolphins.org/river-dolphins-worldwide/tucuxi/
• iucnredlist.org iucnredlist.org/species/10831/50358152

Seed record, before editorial verification. Every number links to its source; report errors on the Corrections page. Methodology · Corrections

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