The symbiotic relationships between tropical reef sponges and cyanobacteria (microalgae) has been well documented. Preliminary evidence suggests that these relationships may be just as common in temperate reef species. Screening of sponges from temperate reefs in New South Wales, Australia, found 5 out of 8 species tested were 'chlorophyll positive'. Of those tested, Cymbastela concentrica (Lendenfeld) had the greatest concentration of chlorophyll-a pigment within its tissue (139.4±9.4μg/g). An estimate of the percentage of temperate reef sponges that potentially contained symbiotic algae was made based on their in situ colour pigmentation. It was predicted that over 65% of temperate reef sponges potentially contain symbiotic algae, although it is unknown how many may be phototrophic.