Learn how volcanic activity has created underwater habitats in this video from NATURE: Sharks of Hawaii. As volcanoes in Hawaii erupted, some of the lava went into the ocean, creating different formation as it flowed. Volcanoes created basaltic planes that living things later turned into coral reefs. In other places, lava created tunnels and tubes as it cooled. Discover the unique adaptations that enable whitetip reef sharks to stay protected in the lava tubes.