Ocean of litter

Plastic bottles are the greatest threat to Polar wildlife

Humans are threatening global biodiversity by providing mobile homes for species that colonize new areas of the world's oceans.

A British Antarctic Survey team found that man-made rubbish in the sea - especially plastics - is spreading "alien" species around the world.

The wrong sort of wildlife

Since the creation of plastics more than 50 years ago, floating litter has provided floating homes for marine organisms such as bryozoans, barnacles, polychaete worms, hydroids and molluscs.

Sir Crispin Tickell: life on earth is becoming less diverse

The rubbish increases the opportunity for dispersal to new areas, according to research published in the journal Nature.

Many species seem to thrive on plastics, and prefer living on them rather than natural materials such as volcanic rock, pumice and wood.

Sir Crispin Tickell, who's a former government adviser on the environment, warned on Breakfast that there's a danger that the world's eco-systems will become less diverse.

We could go back to the situation millions of years ago, when the same sort of organisms were found across the globe.

Threat to the Antarctic

BAS marine biologist David Barnes, who led the research, warned that the influx of foreign junk-riding invaders could threaten indigenous species in some areas.

Currently, alien species were frozen out of Antarctica, but this could change with the predicted 2C temperature increase in the Southern Ocean.

"If freezing sea water temperature is the main barrier to alien organism invasion of Antarctica, polar warming could lessen this constraint," said Barnes.

"Some native Antarctic marine species appear to be very sensitive to even a small temperature increase. If alien species enter the region they have the capacity to drastically and irrevocably change these ecosystems."

The findings were based on a 10-year study of human litter washed ashore on 30 remote islands around the globe, from the Arctic to the Antarctic.