Marine 'jelly balls' found off Australian coast could combat global warming



Large numbers of 'marine 'jelly balls' that have appeared off the east coast of Australia could be part of the planet's mechanism for combating global warming, scientists have said.



The jellyfish-like animals are known as salps, and feed on small plants in the water called phytoplankton (marine algae).

The plants absorb the greenhouse gas carbon dioxide from the atmosphere through the top level of the ocean.

A diver is pictured surrounding by large numbers of salps

Dr Mark Baird of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) said salps were notoriously difficult for scientists to study in the laboratory and little attention has been paid to their ecological role until recently.

Baird was part of a CSIRO and University of New South Wales marine survey carried out last month that found an abundance of salps in the waters around Sydney.

Scientists said their numbers were up to 10 times greater than when first surveyed 70 years ago.

Salps, which are transparent, barrel-shaped animals that can range from one to 10cm in length, are usually found near the ocean's surface and, as a result, can be washed up onto dry land.

A close up of salps, which are transparent, barrel-shaped animals that can range from one to 10cm in length

Their appearance in Australian waters is seasonal but scientists believe the increased numbers are a result of a strong East Australian current, which brings more nutrients to the surface waters for the algae that the salps prefer to eat.

Different species of salp have been found in waters around the world and attention is now being paid to what effect they may have on global warming.

Salps are also of interest because in the Southern Ocean near Antarctica they are thought to be displacing krill, an important food source for many marine animals.



By eating the algae, the salps turn the algae and their carbon dioxide into faeces which drops to the ocean floor. They also take carbon to the floor with them when they die after a short two-week life cycle.

This is thought to be a natural form of carbon sequestration similar to what scientists are trying to do with carbon capture from emission sources such as power stations.

Dr Baird said Australian salps are biologically closer to vertebrates such as humans than to jellyfish because they have the rudiments of a primitive nervous system.

'They are interesting because they are the fastest reproducing multi-celled animal on the planet and can double their numbers several times a day.'

Salps had in the past been considered of little interest because they had fairly low nutrient value and were insignificant as a food source.

He said this was a concern because as the Antarctic ice melted, they were replacing krill, which is a high-nutrient food.