Life underwater is incredible. The creatures that call the ocean home resemble nothing that walks on land or fly through our skies. But much of the ocean’s ecosystems are at risk. Only 2.4% of today’s oceans are marine protected areas or MPAs, protected from certain activities like fishing. Not surprisingly, marine life blooms in these areas, especially if it hosts a diverse array of species, like a coral reef. Research has shown that MPAs increase species diversity and produce bigger fish. Our oceans not only produce half our oxygen but are also are home to a fascinating web of marine life—see some of them in this gallery.