Ocean life

Although the oceans make up by far the largest biome on Earth, only about 20% of Earth’s species live in the oceans, of which about 90% are bottom-living, shallow-water species...

Antarctic life

Lying at the southern end of the Earth, the continent of Antarctica is a huge, mountainous landmass, much of it covered by a permanent ice cap on average about 1.8 kilometres (more...

Arctic life

Much of the Arctic Ocean is covered with a thick layer of floating ice all year round. At its edges, rafts of broken ice, called pack ice, drift in the freezing cold waters. During...

Black smokers

Snaking across the ocean floor is a vast undersea mountain chain known as the Mid-Oceanic Ridge. Here, the Earth’s crust is gradually spreading apart and magma, hot molten rock...

Coral reefs

Coral is found in tropical shallow waters around volcanic islands or close to rocky mainland coastlines. It is made from layers of the skeletons of tiny animals called polyps. Over...

Coral reefs A-Z

Deep-ocean life

Below a depth of about 200 metres (about 660 feet) there is little light, and below 1000 metres (3300 feet) the water is completely black and very cold. Phyto­plankton cannot...

Deep-ocean life A-Z

Endangered oceans

The Earth's oceans have been subjected to extensive pollution in recent years, endangering the lives of plants and animals—and quite possibly storing up harmful consequences for...

Kelp forests

Growing off the Pacific coasts of Russia and California are kelp "forests". Kelp is a kind of seaweed (a form of algae) anchored to the seabed. In some places, the kelp can grow...

Mangroves

Mangrove forests are found on sheltered bays and estuaries along many tropical coastlines. They are formed in places where flowing salt water lays down mud and other sediments...

Ocean floor life

On the ocean floor, on average about 4500 metres (15,000 feet) below the surface, the water is completely black and very cold. Here in the abyssal zone animals cannot use sight to...

Oceanic islands

Cut off from the continental land masses by stretches of ocean water, islands often have a range of plant and animal life that is uniquely their own. Some islands were once part of...

Ocean life A-Z

Plankton

Plankton are mostly tiny plants and animals that float or swim in the surface waters of the ocean. Most ocean animals depend on them, either directly or indirectly, for their food...

Seashore

The seashore is the place where the land meets the sea. It can consist of rocky cliffs, a sandy beach or mudflats bordering a river mouth or estuary. The animals and plants that...

Surface waters

The richest variety of life in the oceans is found in the top 200 metres (about 660 feet): the “roof” of the ocean. Here, light from the sun penetrates the water, allowing tiny...