| 研究実績の概要 |
During the year FY2017, the main focus was to assess the link between energy production in corals and its implication for OA resilience.
This was tested on coral that were assessed as resilient and non resilient by conducting field surveys at two CO2 seeps in Shikine Island and Papua New Guinea. Acroporids were generally found to be less resilient than massive or encrusting corals (such as Poritids). The energy production potential was assessed by measuring mitochondrial electron transport system activity (ETSA). Resilient corals were found to have a statistically significant higher ETSA normalized to biomass (protein content). The effect of transplantation from reference pCO2 to high pCO2 zones was also tested. The ETSA activities, did not significantly change after transplantation. Overall these results suggest that coral resilience to OA may be a innate tolerance provided by a higher ETSA.
To test the second hypothesis on the link of coral morphologies and OA resilience, a custom made flume aquarium, that is suitable to measure pH and dissolved oxygen in the diffusive boundary layer of different corals species (different morphologies) under various flow rates (laminar flow) was built and tested. Moreover, to confirm the general resilience of corals massive vs branching corals, a long term transplantation under elevated CO2 of these two types of morphologies was started at the CO2 seep in Shikine Island. Finally, a long term experiment in the laboratory is being run to test the effect of multiple levels of CO2.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Because the opportunity to go to Papua New Guinea to conduct field survey at the CO2 seeps arised, a higher priority was put on resolving the link between energy production and ocean acidification rather than the morphology effects. Thus CO2 seeps offers a unique opportunity for such study as corals are exposed to life long elevated CO2. On the other hand, the link between morphologies and tolerances to OA, is more suitably tested in the laboratory.
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| 次年度使用額が生じた理由 |
Due to the move of focus towards the link of energy and coral resilience to OA in the FY2017, the budget during the FY2018 will be mainly allocated to the study of the link between morphologies and coral resilience to OA using microsensors techniques. Therefore microsensors probes, pH (unisense, 150,000JPY per probe, 3 months lifetime) and dissolved oxygen probes (unisense, 200,000JPY per probe, 6 months lifetime) will be purchased in addition to a specific software for the measurement using microsensors (unisense TraceSuite, 400,000JPY). Field and laboratory measurement of energy production will still be conducted and therefore consummables for running cost are accounted for a total of 500,000JPY. To be able to conduct field surveys and transplantation at the Shikine CO2 seep, 150,000JPY are planned and finally presentation of the results obtained during FY2017 and FY2018 is planned at the Japanese Coral Reef Symposium to be held in Okinawa and the symposium Ocean in a high CO2 world, and therefore travel expenses is planned to an amount of 400,000JPY
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