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)

Superpowered kissing octopus unveiled for the first time

100 million sharks killed each year, study finds

Clownfish wiggles do an anemone good

Alarming decline of leatherback turtles continues

500-million-year-old sea monster had limbs under its head

Why some fish migrate while others don't

James Cameron's deep sea dive video uncovers new species

Baby whale uses people as pacifiers [Video]

NOAA program could help protect whales

Expedition explores world's deepest hydrothermal vents

Monster goldfish found in Lake Tahoe

Dolphins may call each other by name