Calcification responses of subtropical corals to ocean acidification: a case study from Sesoko Island, Okinawa, Japan

Abstract

We investigated the effect of five levels of pCO₂-adjusted seawater (300 μatm [pre-industrial] to 1200 μatm [near-future]) on calcification rates of six coral species: Acropora nasuta, A. tenuis, Montipora digitata, Pocillopora damicornis, Porites cylindrica, and Galaxea fascicularis, which are common species in the subtropical Ryukyu Archipelago, Japan. In most species, declines in calcification rates were pCO₂-dependent as previously reported. Responses to lower pH seawater significantly differed among species in common-garden tanks. Corals showed both linear and non-linear responses to a wide range of seawater pCO₂, which could be attributable to physiological differences in inter-species. Our results are consistent with previous studies and suggest that the responses of corals to ocean acidification can vary among species.