Marine habitat - Oceans and seas form the largest habitat on the planet.
A large variety of animals live in the marine habitat, from tiny plankton to the largest animal in the world – the blue whale. Fish, whale, shark, jellyfish, crab, starfish, sea turtle, octopus, and seaweed are found in marine habitat.

The massive bleaching hitting the Great Barrier Reef off the coast of Australia is likely that country's "biggest ever environmental disaster," says Dr. Justin Marshall, who has studied the reef for three decades. Only 7 percent of the reef has escaped bleaching, according to researchers at the ARC Center of Excellence. Marshall, a professor at the University of Queensland, says the destructive phenomenon is happening in an area the size of Scotland. "Before this mass bleaching started, we already were at the point of losing 50% of the coral cover on the Great Barrier Reef. This, I think, will probably take another 50% off what was left," Marshall says. Over the course of the last six months, Marshall and his colleagues with the citizen science project Coral Watch have documented the degradation of reef structures near Lizard Island, one of the worst-hit areas. They photographed the same formations of coral multiple times, showing clearly the pace of the destruction.

Ocean Acidification destroying Antarctic marine life

The research took place in the Southern Ocean

Marine snails in seas around Antarctica are being affected by ocean acidification, scientists have found.

An international team of researchers found that the snails' shells are being corroded. Experts says the findings are significant for predicting the future impact of ocean acidification on marine life. The results of the study are published in the journal Nature Geoscience. The marine snails, called "pteropods", are an important link in the oceanic food chain as well as a good indicator of ecosystem health.

"They are a major grazer of phytoplankton and... a key prey item of a number of higher predators - larger plankton, fish, seabirds, whales," said Dr Geraint Tarling, Head of Ocean Ecosystems at the British Antarctic Survey (BAS) and co-author of the report.