This species has been considered a subspecies of Z. californianus, (Z. c. wollebaeki) by many authors. Rice (1998), followed here, argued for the retention of Z. californianus, Z. japonicus, and Z. wollebaeki as distinct species. Recent genetic data support the classification as a separate species (Wolf et al. 2007).
Isabela Island, Galapagos Ecuador
Due to its small-scale occurrence and small, fluctuating population size, and suggested decline of 50% over the last 30 years the Galápagos Sea Lion should be classified as Endangered.