Luis Huckstadt in Santiago, Chile - We are expanding our work with sea lions in the Southern Hemisphere. During the past month of July, we had the opportunity to deploy a new set of satellite tags on sea lions, this time in Chile. South American sea lions, Otaria flavescens, are distributed in both coasts of the South American subcontinent, along the coasts of Peru and Chile in the Pacific, and Argentina, Uruguay, Southern Brazil and the Falkland (Malvinas) Islands in the Atlantic.

Last January, Dr. Dan Costa led our first deployments on the species in Isla de Lobos, Uruguay (see link). During that field season, we successfully deployed 10 satellite tags on female sea lions during early lactation.

Juvenile South American sea lion wearing a tag in Southern Chile.

Photo by Luis Huckstadt

Now, we had the opportunity to conduct a pilot project with sea lions in Chile. The South American sea lion is the only species of pinniped that occurs permanently in Central Chile. Despite its large population (> 300,000 individuals throughout its range), the South American sea lion remains as one of the least studied species of pinnipeds in the world. Our lack of knowledge on the species is even more pronounced in Chilean waters, where most of the world’s population of the species (>100,000 individuals) occur.

This South American sea lion was tagged in Southern Chile.

You can see the Andes in the back. Photo by Luis Huckstadt

The cool thing about this pilot project is not only that this is the first time that this species is tagged along its Pacific range, but also that given the striking differences between the both South American coasts we are expecting these sea lions to do something completely different to their Atlantic counterparts.

We completed our work deploying tags in two different sites along the coast of Chile. The first one, Cobquecura (“place of sea lions”, in the native language, Mapudungun), is located in central Chile, in the upwelling ecosystem. Cobquecura (36°07’S; 74°48’W) is a reproductive colony with a sea lion population estimated in 2,500 individuals.

Juvenile sea lion running towards the sea after release in Cobquecura, Central Chile.

Photo by Luis Huckstadt. 

The second field site is the island of Chiloe, specifically in the Gulf of Ancud (41°52’S; 73°50’W), in the Northwestern tip of the island. Our work on this second field site resulted as an invitation from Drs. Doris Oliva and Maritza Sepulveda, from the Universidad de Valparaiso (Chile). Drs. Oliva and Sepulveda are leading a novel project to investigate the interaction between sea lions and fish farms in southern Chile using satellite telemetry.

Our main goal with this new set of deployments is to investigate both the ecological and physiological factors that determine the foraging behavior of the South American sea lion along the Chilean coast. We will determine which oceanographic features are associated with foraging and searching behavior, we will determine whether the animals are foraging on the benthos (i.e. sea bottom) or in the epipelagic zone (i.e. water column). Finally, we will examine to what extent animals are pushing their physiological capability.  

Map with the last locatios of sea lions tagged in Cobquecura, Central Chile.

The flags indicate the locations of the animals as of August 7th, 2009 (after three weeks at sea).

The deloyment location (Cobquecura)

is also indicated in the map.