Sea lion hunting by the Europeans at the Atlantic coasts of South America started in the 19th Century and continued up to the second half of the 20th century in Argentina and Uruguay. The practice changed nutrition guidelines of these pinnipeds as well as the structure of the coastal trophic network, according to the studies by the team co-directed by Lluís Cardona from the University of Barcelona (IRBio), and Enrique Crespo from the Patagonian National Center and the National University of Patagonia (Argentina).