Marine Life

Coral colony

Marine life refers to the collection of organisms that inhabit Earth's oceans. The World Ocean blankets more than 70 percent of the planet's surface, comprises 99 percent of its living space and hosts almost half of its species. Thus oceans are collectively Earth's largest habitat. According to the first Census of Marine Life, the total number of known marine species is around 250,000.

Marine life is categorized into three basic types: plankton, nekton and benthos. Plankton are organisms that float, relying on wind, currents and waves to move them around. Nekton are large, complex animals that actively and freely swim in water. Benthos are organisms that reside on the seafloor; they either burrow, crawl or are fixed in one place. In addition, many different types of ecosystems can be found throughout the oceans. (Photo: Shutterstock)

Earth's tiniest porpoise approaches extinction

How to nap like a sea otter pup

Rare encounter with piglet squid leaves deep sea explorers at a loss for scientific words

Newly discovered shark puts on a light show to lure in its next meal

Astonished divers come across a massive jellyfish off the coast of England

Loggerhead sea turtles nesting in record numbers in Southeast

A little-known fish takes a star turn by eating a shark in one gulp

7 clever behaviors of octopuses

This newly identified critter eats rocks and secretes them as sand

7 haunting songs sung by whales

8 mind-boggling dolphin facts

Canada bans all captive whales and dolphins