Researchers have uncovered a rarely seen Antarctic gem — on the ocean floor.

While the icy continent is known the world over for its white landscapes and distinctive wildlife, scientists have stumbled on a technicolour underwater ecosystem, and all by accident.

Australian Antarctic Division (AAD) biologist Dr Glenn Johnstone said the research team was retrieving a data recorder from waters near the Casey Research Station and sent down a camera with lights to record the mission.

When both devices resurfaced he saw the camera had recorded a lush seabed field of urchins, starfish, worms, algae and sponges.

"All of the colour in Antarctica, all of the diversity, is actually on the sea floor," Dr Johnstone said.

"When you're up above there's very little colour. There's whites and blues and greys. All the animals are black and white, and as cute as they are, the real diversity and the real health of the environment is down on the sea floor."

Dr Johnstone said the complex underwater ecosystem would be a good future indicator of changes in climate and ocean acidification.

Results from the data recorder would be analysed at the AAD in Hobart, he said.

Dr Johnstone said the ecosystem's location — under a 1.5-metre ice sheet the researchers drilled through and at a 30-metre depth in a bay about five kilometres from Casey — was ideal for it to flourish.

"It's an area that we have been working very close to for a long time, but we've never actually dived or put any cameras down," he said.

"It was a great surprise to find such a beautiful, vibrant environment."