Researchers from the Centro Nacional Patagónico (Cenpat-Conicet) have recorded for the first time pumas hunting live salmon in the rivers of Patagonia. This finding is unprecedented in the world, as in other regions of the northern hemisphere, where salmon and felines coexist, this interaction had never been documented.
The Chinook salmon (Oncorhynchus tshawytscha), native to the North Pacific, is an invasive fish that can exceed 60 kilograms in weight and 1.5 meters in length. Its expansion in Patagonian rivers, from the north to Tierra del Fuego, is forcing terrestrial predators to modify their eating habits.
The Discovery
- Since 2003, researchers had detected salmon carcasses far from the rivers, suggesting the intervention of a large predator.
- In 2022, a fisherman first spotted pumas hunting salmon, confirming the suspicions.
- Trap cameras installed by the team of Javier Ciancio (Cesimar-Conicet) recorded the activity of scavengers and predators around the fish remains.
This cryptic behavior indicates that some pumas have begun to specialize in this unusual prey, a phenomenon that could be occurring in other rivers without being detected.
Ecological Impact of the Chinook
The invasion of the Chinook salmon began about 45 years ago and represents the largest expansion of salmonids worldwide. Its effects are multiple:
- Alteration of river ecosystems: it modifies the water chemistry during spawning and mass death.
- Feast for scavengers: in sections of the Santa Cruz River, up to 20 tons of carcasses were counted, providing food for condors, foxes, caracaras, and black-chested buzzard-eagles.
- New trophic interactions: the appearance of pumas hunting salmon reveals how an invasive species can reorganize ecological relationships.
A Paradox for Environmental Management
The Chinook presents a dilemma in Argentina:
- For science, it is a threat to native biodiversity and an ongoing ecological experiment.
- For sport fishing, it is a valuable resource, considered a trophy for its size and strength.
This duality complicates management strategies, as what is an economic and recreational attraction for some is an environmental risk for others.
Patagonia as a Natural Laboratory
The region becomes a unique scenario to observe how an exotic species can alter the balance of life. Researchers agree that the effects of this invasion are profound: it is not just about adding a species to the ecosystem, but about reorganizing energy flows and trophic relationships.
The record of pumas hunting Chinook salmon in Patagonia is a finding that opens new questions about the interaction between predators and invasive species. Meanwhile, the expansion of the Chinook continues to be a challenge for conservation and environmental management, in a territory that is consolidated as a natural laboratory of ecological changes.
