A bacteria that causes a disease in hard corals could become more successful as sea temperatures rise and the pH of the oceans drop.
Scientists at the Florida International University's Department of Biological Sciences found that Aurantimonas coralicida, the bacteria responsible for a coral disease white plague type II, grows best when water is warmer than normal, and can tolerate a low pH.
The study by Remily and Richardson, which is due to be published in the journal Microbial Ecology later this year, used pure cultures of the coral pathogen to determine how its growth differed when the temperature, pH and oxygen levels changed.
The results showed that Aurantimonas coralicida reproduces fastest when the water temperature is between 30 and 35C and when the pH is between 6.0 and 8.0.
As the temperature gets higher, a synergistic relationship with pH occurs and the pH tolerance goes from a minimum of 6.0 down to a minimum of 5.0.
The experts fear that changing environmental conditions on reefs, which include both rising sea temperatures and dropping pH levels caused by global warming, may be promoting the growth of bacteria that cause coral diseases and allowing them to expand their niches.
For more details on the discovery see the paper: Remily ER, Richardson LL (In Press) - Ecological Physiology of a Coral Pathogen and the Coral Reef Environment. Microb Ecol. 2006 Apr 6; ahead of print.