The common bottlenose dolphin (Tursiops truncatus) is a cosmopolitan species that does not range to latitudes greater than 45º in either hemisphere, with a few exceptions. In South American waters, this species is generally distributed in the Atlantic Ocean south to Chubut province (ca. 46º S), while in the eastern South Pacific this species has been recorded in northern and central Chile, with a few records south to 40º S. Here we summarize recent records of common bottlenose dolphins obtained during systematic marine mammal surveys in the Chilean Patagonian and Fuegian channels and fjords (the Los Lagos, Aysén, and Magallanes regions of Chile). These data suggest an extension of the documented range of the species southwards, indicating that bottlenose dolphins may have colonized new areas in the eastern South Pacific or as the result of an increase in survey efforts by scientists in the region.6 page(s

Species distribution modeling helps understand how environmental factors influence species distribution, creating profiles to predict presence in unexplored areas and assess ecological impacts. This study examined the habitat use and population ecology of the Chilean dolphin in Seno Skyring, Chilean Patagonia. We used three models—random forest (RF), generalized linear model (GLM), and artificial neural network (ANN)—to predict dolphin distribution based on environmental and biotic data like water temperature, salinity, and fish farm density. Our research has determined that the RF model is the most precise tool for predicting the habitat preferences of Chilean dolphins. The results indicate that these dolphins are primarily located within six kilometers of the coast, strongly correlating with areas featuring numerous fish farms, sheltered waters close to the shore with river inputs, and shallow productive zones. This suggests a potential association between dolphin presence and fish-farming activities. These findings can guide targeted conservation measures, such as regulating fish-farming practices and protecting vital coastal areas to improve the survival prospects of the Chilean dolphin. Given the extensive fish-farming industry in Chile, this research highlights the need for greater knowledge and comprehensive conservation efforts to ensure the species’ long-term survival. By understanding and mitigating the impacts of fish farming and other human activities, we can better protect the habitat and well-being of Chilean dolphins.

The distribution of huillín (Lontra provocax) and chungungo (Lontra felina) in the marine environment of Aysén and Magallanes during 1977-82 and 2001-22 is analyzed. 85.3% of the huillín sightings were solitary individuals and 13.6% were females with 1-3 offsprings. 90% of the chungungo sightings were solitary animals and 10% were females with 1-2 young. The huillín has a continuous distribution in fjords and southern channels, with a marine population probably greater than the continental one. The chungungo uses the ocean coast from the Guaitecas Islands to Cape Horn. Both species were found sympatrically on the Hermanas, Velasco, Mornington, Beauclerck and Contreras islands. The Protected Areas in Chile are mostly terrestrial, and its importance for otter protection and its habitat is discussed. By their definition the Multiple Use Marine Protected Areas include productive activities, without certainty about their efficiency in protecting huillín/chungungo. The “Francisco Coloane” Marine Park, of only 1,506 hectares, represents the only sector in which the huillín has absolute protection, and the “Kawésqar” National Reserve, which covers the maritime territory around the “Kawésqar” National Park, brings together 82% of the salmon farming concessions in Magallanes, so its importance for the protection of huillín/chungungo is questionable. Various activities and projects under development in the Aysén/Magallanes region are exempt from submission to the Environmental Impact Study System. The study of 1,563 projects related to marine and freshwater habitats, mentioned the huillín in only 5.4% and chungungo in 12.6% of the cases. 0.94% mentioned adverse effects, none of them on the huillín/chungungo, without mitigation, protection and/ or conservation measures for these species. It is concluded that the situation of the huillín/chungungo in Southern Patagonia requires a thorough review of protection measures, with the establishment of protected areas and biological corridors between sectors and continental populations