Sea lions can hold their breath for up to 20 minutes. Unlike dolphins, sea lions exhale before diving. Their nostrils have special muscles to open them in order to breathe.
Sea lions can dive to depths over 250m, these animals have a high tolerance for carbon dioxide.The oxygen in their body concentrates in their heart and central nervous system rather than in non-vital organs. Their relative, the elephant seal, can hold its breath for 62 minutes and dive to depths over 1200m