Almost 9 months have passed since September 2025, when we deployed satellite transmitters on 30 Southern Right Whales in Golfo Nuevo (Chubut, Argentina). As of today, 5 whales still have active transmitters: Silicon, Bismuth, Aluminium, Radon and Sodium. Sodium has completed her migratory journey, returning to Golfo Nuevo on May 25, 2026.

Except for Sodium, the four whales that continue transmitting remain far from Peninsula Valdés. Since April 26, Silicon has remained over the continental shelf between the mainland and the Islas Malvinas (Falkland Islands). After traveling within the deep ocean basin and over the continental shelf, Bismuth traveled southeast until reaching the western edge of the Islas Georgias del Sur (South Georgia). Aluminium is another of the whales which utilized both the deep ocean basin and the continental shelf and is now south of the Islas Malvinas (Falkland Islands). Finally, after leaving the Península Valdés breeding grounds, Radon remained over the continental shelf, and after passing close to the north of the Islas Malvinas (Falkland Islands), continued traveling south towards the Scotia Sea.

The devices on 11 of the whales ceased transmissions while the individuals were still within Golfo Nuevo. The majority of these were short-duration transmitters and allowed us to learn more about the whales’ movements within the breeding area. Among these, the most notable case was Mercury, a female with calf, that was monitored for almost 3 months.

The 14 remaining whales began their migratory travels, leaving the waters of Valdés, although contact with their transmitters was lost after varying tracking periods. Some transmitters, like those of Iridium and Argentum, only recently stopped functioning, having actively transmitted information for nearly 8 months. The migratory journeys of most of these individuals indicate that their preferred feeding areas are the waters over the continental shelf, the continental slope, and the deep ocean basin off the Patagonian coast.