Commerson’s dolphins and Peale’s dolphins – Argentina

Both Commerson’s and Peale’s dolphins occur in the coastal waters of Southern South America and Falkland Islands/ Islas Malvinas. Commerson’s are also recorded around the Kerguelen Islands in the Southern Indian Ocean. Their relatively limited distribution makes them highly vulnerable. They are found along cold temperate waters to sub Antarctic waters, exclusively in the Southern Hemisphere.

Generally speaking, all coastal cetaceans face numerous threats such as bycatch in gillnets, habitat degradation, pollution, seismic exploration and emerging diseases among others. Of the threats mentioned, throughout the project the two main ones that would be affecting Commerson's and Peale's dolphins, as well as other species of cetaceans in the area, are by-catch and seismic exploration. The presence of some of these threats has been cyclical; for example, bycatch in gillnets has increased during the socioeconomic crises in Argentina.

The over-arching aim of this work is to increase knowledge on these and other species of cetaceans of Southern Patagonia to better understand the impact that human threats might have on them and help to find solutions to mitigate these threats.

Additionally, information on stranded cetaceans is collected during beach surveys in the Santa Cruz province. This allows us to have a better idea of cetacean diversity within Patagonian waters by recording not only species that are regularly seen within the area but also rare species such as: spectacled porpoise, Shepherd’s beaked whale, strap-toothed beaked whale, Cuvier’s beaked whale, sei whale and humpback whale, among others. Samples collected from these stranded and dead animals are analysed, and, where possible, a necropsy is performed.