Exploitation and Recovery of the South American Sea Lion in the Southwestern Atlantic

Abstract

The South American sea lion, Otaria flavescens, is one of the most conspicuous marine mammals along the coasts of the Atlantic and Pacific Oceans. It has a long history of exploitation throughout its range. In the southwestern Atlantic it was heavily exploited throughout the first half of the twentieth century. As a K-strategist subject to exploitation this population fell to very low levels. After protection was instigated, recovery was at first very slow. At the time of writing, the population size is about one third of the original size. The opportunistic and plastic behavior of the South American sea lion together with a high level of juvenile survival resulted in a faster rate of population recovery in the most recent decades. Possible reasons for this improved survivorship may include an increase in the availability of food resources, prey-switching, and a decrease in exogenous causes of mortality.