Sei whale stranded in San Isidro, Argentina dies despite rescue operation

A sei whale (Balaenoptera borealis) became stranded on a sandbank in the Río de la Plata near San Isidro, Argentina, in late July 2026. The animal, about seven metres long, was first sighted on a Friday and an emergency rescue was launched by the Argentine Naval Prefecture (Prefectura Naval Argentina) together with the conservation group Fundación Temaikèn.

Rescuers kept the whale's skin moist, monitored its condition continuously and waited for favorable tides to attempt a tow. Despite two days of intensive effort, the whale died on Sunday. Fundación Temaikèn said, “Nuestro equipo acompañó al ejemplar durante todo el operativo. A pesar de los esfuerzos realizados, el animal no logró sobrevivir.”

The incident highlights the challenges of marine wildlife rescue in the region, where sei whales regularly migrate along the coasts of Argentina, Uruguay and Brazil and can become disoriented by environmental or health issues.