Researchers are about to head to the Great Pacific Garbage Patch to spend a month analysing the huge build-up of rubbish that's polluting the ocean.

The patch, also known as the Pacific Trash Vortex, was discovered in 1988 by Captain Charles Moore of the Algalita Marine Research Institute in California.

Since then, the patch has grown in size and is estimated to be at least 700,000 square kilometres.

"We're dealing with more than just a little bit of rubbish out there in a few places in the ocean," Captain Moore told Radio Australia's Pacific Beat.

The patch is located in the North Pacific Ocean and is made up of huge concentrations of plastic waste and sludge.

"We are trying to tell people what's going on."

Captain Moore says marine life is feeding on the garbage patch, effectively putting organisms of the ocean on a plastic diet.

"35 per cent of the fish that we caught out there had an average of two pieces of plastic in their stomach," he said.

"We're dealing with a new phenomenon. Really, a new habitat that is unknown in the history of the planet."

Computer modelling also suggested debris washed out to sea from the 2011 tsunami also drifted towards the vortex.

"This is sort of humanity's footstep in the ocean. We do want to make humanity aware that they are having a plastic footprint on the planet,"

Captain Moore and his team will head to the ocean garbage patch in early July.