WCS Argentina

Southern Elephant Seal

The southern elephant seal is the largest of seals and a species that exhibits the greatest sexual dimorphism in mammals. The male averages around 3.5 tons (7,000lbs) and can measure up to 5.5 meters (18feet). Females are a lot smaller weighing less than 900 Ks (less than 2,000lbs) and measuring less than 3 meters (9 feet).

Adult males have a large proboscis or trunk that acts as a sound box for its loud belching roars to defy competitors. During the breeding season a male can gather more than 50 females with which it mates once the calves reach the end of their nursing period. Elephant seals feed at great depths possibly on bio-luminescent prey (fish and squid).

The species has a circumpolar distribution and breeds primarily on sub-Antarctic islands; however Peninsula Valdes has the only breeding colony on a continent other than Antarctica, and one of the largest. Elephant seals were hunted extensively for oil from the beginning of the XIXth century and until the middle of the XXth century. Island colonies in the South Atlantic have recovered. In the case of Peninsula Valdes, elephant seals were not hunted intensively (as it did occur with sea lions). The population on Peninsula Valdes has continued a recovering since the early XXth century when this colony began to develop.

Conservation Challenges

Many marine birds and mammals cover large distances to reach their feeding and breeding areas. They are called "trans-zonal" species because they cross multiple jurisdictions, high seas or international waters. Amongst the species dependent on the Southwestern Atlantic system, the best known is the southern elephant seal whose dispersion covers millions of square kilometers.

Conservation of migratory species poses significant challenges since it requires joint efforts of countries and international organizations, regulatory frameworks and the coordinated management of shared resources. Southern elephant seals are an excellent model to test the ability to find new ways to address the conservation of oceanic environments and of widely distributed species.

Conservation Approach

WCS uses the scientific knowledge developed over decades of research of the biology of southern elephant seals and behaviors at sea to raise awareness on the need to not only protect breeding sites but also marine areas where they feed.


To ensure the protection of breeding colonies of southern elephant seals on the Patagonian coast and ensure effective conservation of ocean areas relevant for food and survival.


In cooperation with researchers from the region, for decades WCS monitors the population of southern elephant seals off the coast of Peninsula Valdes. In addition, WCS has conducted research on the annual cycle of behavior of this species at sea through dive recorders and satellite tracking during the pelagic stage (at sea).

WCS also works on the analysis of threats to wildlife both on land and at sea, and interacts with governments and institutions providing expert knowledge and promoting the conservation of species and habitats.


Peninsula Valdes southern elephant seals feed in the productive areas of the continental shelf, its edge and slopes and the deep water fishing areas of prime importance to the fishing industry.

The large-scale commercial fishing directly impacts on natural populations as a result of decreasing resources or prey availability.

Also as a result of interaction with large squid fisheries or debris floating adrift, it is increasingly more frequent to see elephant seals entangled in fishing gear. The effect of entanglement can result in short term death of the individual or reduce its survival.

On the coast, the main threat to southern elephant seals is in the areas where there is no protection and disturbance caused by human activities causes offspring to be abandoned at their lactation stage.


Research conducted by WCS in collaboration with other investigators of this species in Patagonia has revealed aspects of its fascinating behavior and capacity to adapt. They remain several months at sea and travel distances of over 6,500 km (4,000 miles), are known to dive to depths of up to 1,500 m (5,000 feet). The average duration of dives is 20-30 minutes, but they can remain submerged for over an hour.

In parallel, WCS works to consolidate coastal protected areas and promotes proposals to expand protection to offshore environments.


WCS Argentina
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Key Staff

Claudio Campagna
Director, Sea and Sky Program
All Southern Elephant Seal Staff >>

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