California sea lion in a forest of giant kelp, Baja California, Mexico

© Claudio Contreras/Minden Picture

Sea lion in a kelp forest, Baja California, Mexico

Take a stroll along almost any marina from Costa Rica to Alaska, and you'll likely hear the playful barks of sea lions echo through the air. California sea lions, like the one pictured, are a common sight basking in the sun along the rocky shores of North America's western coast. These marine mammals, belonging to the pinniped group, are often mistaken for seals. An easy way to distinguish between them is by looking at their ears—sea lions have visible flaps, seals don't.

Sea lions also have a special relationship with giant kelp, seen in today's image from Baja California, Mexico. These towering underwater plants, which can grow up to 53 metres in ideal conditions, sway gently with the currents, creating beautiful scenery. Kelp forests are home to a diverse array of marine life, including sea lions, tiny invertebrates like snails, prawns and jellyfish and a wide range of fish, like cod, rockfish and wrasse. Sea lions twist and turn through the thick kelp strands, hunting fish hiding within the leaves. These marine mammals also use kelp as refuge from predators like sharks, blending in with the fronds of the brown algae to avoid detection. Kelp's rapid growth makes it an ideal habitat for marine life of all types to thrive.