The Southern Ocean is the most recently named of the five oceans. It used to be considered part of the world's three largest oceans. In 2000, the International Hydrographic Organization decided that the Southern Ocean is distinct from these oceans. The Our Five Oceans series features stunning visuals, detailed maps, educational debates, and challenging research activities. Each book explores key topics such as ocean life, ecosystems, and environmental issues, in order to help readers better understand the importance of protecting the world's oceans.