Symbiodinium Community Composition in Scleractinian Corals Is Not Affected by Life-Long Exposure to Elevated Carbon Dioxide

• DOI: 10.1371/journal.pone.0063985
• Publication Date: 2013-05-22T22:38:42Z
• Authors: Sam H. C. Noonan; Katharina E. Fabr...; Craig Humphrey
• Keywords: Symbiodinium; Ocean Acidification; Anthozoa

Ocean acidification (OA) is expected to negatively affect coral reefs, however little known about how OA will change the coral-algal symbiosis on which reefs ultimately depend. This study investigated whether there would be differences in Symbiodinium types response OA, potentially improving performance. We used denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) region ribosomal DNA investigate dominant associating with six species scleractinian that were exposed elevated partial pressures carbon dioxide (pCO2) situ from settlement and throughout their lives. The was conducted at three naturally occurring volcanic CO2 seeps (pCO2 ∼500 900 ppm, pHTotal 7.8 - 7.9) adjacent control areas ∼390 ∼8.0 8.05) Papua New Guinea. associated corals living an extreme seep site >1000 ppm) also examined. Ten clade C D dominated 443 samples. strongly contrasted between species, however, no observed due exposure. Within five 85 95% samples exhibited same type across all sites, remaining rare having patterns attributable sixth displayed specific types, unrelated inhabiting found commonly moderate areas. Our finding symbiotic associations did not exposure suggest that, within hosts, none 13 had a selective advantage high pCO2. Acclimatisation through changing association therefore does seem option for Indo-Pacific deal future OA.