VAST numbers of marine "jelly balls" now appearing off the Australian east coast could be part of the planet's mechanism for combating global warming.

The jellyfish-like animals are known as salps and their main food is phytoplankton (marine algae) which absorbs the greenhouse gas carbon dioxide in the top level of the ocean. This in turn comes from the atmosphere.

Mark Baird of the CSIRO said salps were notoriously difficult for scientists to study in the laboratory and consequently little attention has been paid to their ecological role until recently.