Rising sea temperatures threaten sponge survival: study

ABC Net 21 Aug 08;

Marine researchers have found that rising sea temperatures pose a direct threat to reef sponges.

The Australian Institute of Marine Science (AIMS) has found that water temperatures of 33 degrees or higher cause the relationship between sponges and microbes to break down, similar to coral bleaching.

Sponges are considered to be the great cleaners of the ocean, with a one kilogram sponge filtering 24,000 litres of seawater a day.

AIMS researcher Dr Nicole Webster says once the symbiotic relationship collapses, the sponge starts to die and less desirable forms of bacteria take over.

"A lot of the known symbionts disappeared and we also saw the appearance of new microbes that tended to have fairly high similarity to bacteria that have previously been isolated from diseased and bleached corals," she said.