title: Effects of acidified seawater on coral calcification and symbiotic algae on the massive coral Porites australiensis.
abstract: We investigated the effect of acidified seawater on calcification and symbiotic algae (zooxanthellae density, chlorophyll content per single algal cell, fluorescence yield (Fv/Fm)) on a massive coral, Porites australiensis, a common species in the Ryukyu Archipelago of Japan. We found that acidified seawater significantly decreased the calcification and fluorescence yield, but did not affect zooxanthellae density and chlorophyll content per single algal cell. This indicates low levels of photoacclimation to acidified seawater in this species, and this is contrary to the findings of previous studies of Acropora species. A significant correlation between calcification and fluorescence yield was observed, indicating the presence of a strong relationship between calcification and algal photosynthesis. Our results indicate that endosymbiont photosynthetic dysfunction may enhance the decrease of coral calcification in future acidified ocean conditions. Calcification and fluorescence yield among colonies clearly differed, showing that the response to acidified seawater is highly variable among colonies in natural coral populations.
authors: Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 905-0227, Japan. iguchi.a0218@gmail.com
authors: Akira
authors: A
authors: Iguchi
authors: Saori
authors: S
authors: Ozaki
authors: Takashi
authors: T
authors: Nakamura
authors: Mayuri
authors: M
authors: Inoue
authors: Yasuaki
authors: Y
authors: Tanaka
authors: Atsushi
authors: A
authors: Suzuki
authors: Hodaka
authors: H
authors: Kawahata
authors: Kazuhiko
authors: K
authors: Sakai
mesh_terms: D000143:Acids / Q000378:metabolism; D000818:Animals; D037421:Anthozoa / Q000378:metabolism / Q000502:physiology*; D002113:Calcification, Physiologic / Q000502:physiology*; D000460:Chlorophyta / Q000502:physiology*; D012623:Seawater / Q000737:chemistry*; D013559:Symbiosis
chemical_list: D000143:Acids