Rising sea levels are caused by both ice melt and thermal expansion of warming ocean water.

Prehistoric coral reefs were similar to modern reefs.

The Pacific Ocean is larger than all the Earth's landmasses combined.

Sea horses swim upright rather than horizontally.

The Arctic Ocean may be ice-free in summer within decades, creating new shipping routes and accelerating warming.

Exploration of the deep sea has revealed that bioluminescence is far more common than previously thought — it may be the dominant form of communication in the ocean's depths.

A sea horse anchors itself using its tail.

The Great Barrier Reef has experienced multiple mass bleaching events since 1998 as sea temperatures rise.

Sea turtles can migrate thousands of miles between feeding and nesting areas.