| 研究実績の概要 |
We investigated the effects of ocean acidification on hermatypic corals and potential physiological characteristics that can explain the resistance of some coral species.
Although there is a consensus in the literature that the effect of ocean acidification on coral reefs and scleractinian corals around the world will be mostly negative, several studies also showed species-specific responses, with some corals being less affected by ocean acidification. As a result, ocean acidification would alter the structure of coral communities with only the most resistant remaining. Such selection of resistant species has been shown in naturally acidified areas such as CO2 seeps where ‘winner’ species dominates the acidified areas, whereas ‘loser’ species that were dominant in control areas are absent.
We first identified loser and winner species at three CO2 seeps in Japan, Italy and Papua New Guinea. We then showed that winner species have a higher mitochondrial activity per biomass compare to loser species that could allow them to allocate more energy towards calcification and inorganic growth. Moreover we showed that this characteristic cannot be acquired through even a life time exposure to ocean acidification and such chronic stress strongly disfavour loser species by limiting both their inorganic and organic growth. We also showed using microsensors techniques that the early planula stages of two loser species showed elevated respiration rates under elevated pCO2 and that it could affect their ability to detect chemical cues required for a succesful settlement.
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