Hunting and fishing activities cause dietary changes in South American fur seals and sea lions
Researchers of the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona reconstructed the dietary habits of South American sea lions and seals in the area of Rio de la Plata (Uruguay) over the last 7,000 years. The results show that these species’ diets were different until late 20th century, when they started coinciding without overlapping each other.
According to the study, published in the journal Journal of Animal Ecology, changes in the source distribution could occur due the bottom-trawling and hunting of these animals –which started in the 18th century and lasted until the second half of the 20th century in Argentina and Uruguay. These findings could explain the differences in the tendencies of both species in the south-western Atlantic Ocean, where sea lions would adapt better to the changes in the food network, caused by the human impact. This information is relevant to design proper measures for the management and preservation of these ecosystems.
UB-IRBio researcher Massimiliano Drago is the first author of the study, in which the experts Lluís Cardona and Lisette Zenteno (UB-IRBio), and Pablo Inchausti (University of the Republic, Uruguay) and others have also taken part.
Photo: These findings show that seals (A. australis) seem to show a bigger dietary plasticity. Image: Massimiliano Drago, UB-IRBio.