The deep sea is a mysterious place
Coral reefs are diverse ecosystems
Salt marshes change with the tides
Oceans are filled with fascinating creatures
Estuaries are the nurseries of the sea
Lagoons come in many shapes and sizes
Food is plentiful in intertidal zones
Marine plants provide safe havens for animals
People and animals depend on mangroves
The sea floor is mountainous in places
Humans affect most marine ecosystems
People can help care for marine ecosystems.