Massive sea lion and fur seal hunting in the Patagonian coasts is altering Southern Atlantic Ocean

Sea lion hunting by the Europeans at the Atlantic coasts of South America –it started in the 19th Century and continued up to the second half of the 20th century in Argentina and Uruguay- changed its nutrition guidelines of these pinnipeds as well as the structure of the coastal trophic network, according to the studies by the team codirected by Lluís Cardona, from the Department of Evolutionary Biology, Ecology and Environmental Sciences and the Biodiversity Research Institute of the University of Barcelona (IRBio), and Enrique Crespo, from the Patagonian National Center and the National University of Patagonia (Argentina). The results of this study are shown in two articles, published in the scientific journals Oecologia and Paleobiology, its co-authors being Fabiana Saporiti and Lisette Zenteno (UB-IRBio), and Damian G. Vales (Patagonian National Center), among others.

Hunting and fishing usually create a reduction in the abundance of bigger species. Therefore, megafauna is considered to be one of the most threatened compounds of biodiversity. Marine mammals are an essential element of megafauna in all oceans and they have been extremely exploited by humans. However, knowing about the effects of this exploitation on the functioning of food networks in marine ecosystems –a high complex structural framework- is still a hard challenge for the scientists due to the difficulty to perform manipulative experiments.

In the new studies, the scientific team shows the ecological effects of marine resource exploitation in the southern coasts of South America over the last 6000 years, focusing on two species, hunted by both aboriginal hunter-gatherers and European colonizers: the South American sea lion (Otaria flavescens) and the South American fur seal (Arctocephalus australis).



Further information

Picture: Lluís Cardona