While most seals make their homes in colder climates, the Hawaiian monk seals prefer the warm, sandy beaches of the Northwestern Hawaiian Islands.
A baby harp seal rests on the Arctic ice. Its mother can distinguish it from hundreds of others by scent alone.
Leopard seals, named for their spotted coats, are one of the primary predators of Antarctica.
Weddell seals are known for their docile nature and are easily approached by humans.
Fastest of the seals and sea lions, California sea lions can be seen gathered in colonies along the Pacific coastlines of North America.
"These animals are always yelling at each other," writes photographer Joel Sartore of the Steller sea lions on Alaska's Lowrie Island. Here, two females go nose-to-nose over a disputed bit of territory in a crowded rookery. Alaska's Steller sea lion populations have been in precipitous decline over the last 30 years, and scientists are at a loss to explain the cause.
A large population of California sea lions inhabits the Galápagos Islands. This group is categorised as a separate subspecies from its relatives along the North American coast.
Fur seals belong to the class known as eared seals and have excellent hearing and sharp eyesight. They live in colonies on rocky beaches, but will spend weeks at a time in the water hunting.
At home on the coasts of Mexico and southern California, a northern elephant seal and her pup remain close together during the three months the pup nurses.
The largest true seal, elephant seals can barely move on land but are strong, agile swimmers. Males are much larger than females and have a trunk-like nose, from which the species gets its name.