The ocean covers 71% of the Earth's surface, yet humans have only mapped a small percentage of the ocean floor.
From shallow coastlines to deep sea trenches, the ocean floor offers diverse, often extreme ecosystems, where many of the world's strangest creatures survive and flourish.
What lives in the ocean's most extraordinary oases?
What mysterious phenomena are hiding at the bottom of the ocean?
When you stand on the beach and look across the ocean's surface, you may see nothing but shimmering water, stretching beyond the horizon; but under the surface, the ocean is teeming with spectacular organisms, thriving inside a wide array of complex and delicate ecosystems. Along coastlines, estuaries, and islands, marine plants and animals flourish in sunny, shallow waters.
The bright sunlight nurtures many vibrant ecosystems, but none as biodiverse as tropical coral reefs, the rainforests of the sea.
Coral reefs are living ecosystems, built by hard, colorful coral.
Often mistaken as flora, corals are marine invertebrates that grow in tight clusters along the ocean floor.
Warm-water corals maintain a symbiotic relationship with microscopic algae called zooxanthellae.
Zooxanthellae live safely inside coral tissue, providing their hosts with oxygen and energy.
