2018 Fiscal Year Research-status Report
Identifying "super corals" in Mauritius: what physiological factors promote high recovery after bleaching?
| Project/Area Number |
18KK0298
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| Research Institution | Shizuoka University |
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Principal Investigator |
CASARETO Beatriz 静岡大学, グリーン科学技術研究所, 教授 (60402244)
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| Co-Investigator(Kenkyū-buntansha) |
藤原 健智 静岡大学, 創造科学技術大学院, 教授 (80209121)
鈴木 利幸 静岡県立大学, 食品栄養科学部, 研究補助員 (80537283)
RAMPHUL CHITRA 静岡大学, 創造科学技術大学院, 研究員 (20832661)
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| Project Period (FY) |
2018-10-09 – 2021-03-31
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| Keywords | Mauritius / super coral / coral bleaching / oxidative stress / thermal tolerant / genome analysis / physiological factors / Symbiodinium database |
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| Outline of Annual Research Achievements |
In this research we intend to identify “super corals” in Mauritius’ reefs. From March 9 to 16, 2019 we surveyed two reefs sites: Albion (shallow, human impacted) and Belle-Mare (deep, less affected). In Albion the seawater temperature was 30.02 °C (shore) and 29.36 °C (reef flat) and the light intensity was 1167, and 1536 micromol cm-2 sec-1 for the same sites. Coral coverage was around 5%. Almost massive corals as Porites were found in the near shore and middle lagoon. In the reef flat, Pocillopora, Montipora and a few Pavona were observed, but Acropora corals were not present. Low coral coverage and diversity characterized this reef. 17 coral samples were taken. Average photosynthetic performance (Fv/Fm) was 0.5. Glycerol/glucose ratio (higher for stressed corals) was 0.53.
In Belle Mare water temperature was 29.5 °C and the light intensity was 1231 micromol cm-2 sec-1 in the reef flat and 30.6°C and 486 micromol cm-2 sec-1 in the near shore. In the reef flat the coral coverage was from 80% to 100% with high species diversity (Acropora, Montipora, Pocillopora, Pavona and Fungia). Bleached and healthy colonies were found. 19 coral colonies were sampled in this reef. In the near shore coral coverage was 30-40%, dominated by branching Acropora. In average, Fv/Fm was 0.6. Gly/glu ratio was 0.52 but high values were also found (1.41 and 0.94) in massive corals. In spite of that they were healthy. A preliminary genomic analysis indicted that zooxanthellae from clade C were dominated in Albion, whereas clade D and mixture D and C were more abundant in Belle Mare.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
We had successfully surveyed two targeted reefs and had obtained very valuable information about reefs physico-chemical and biological conditions, coral diversity, corals physiological conditions and responses to stressors of each area. We had also identified those corals that could be categorized as “super corals” and now we are processing data on genomic analysis together with other physiological parameters that will serve as base for the categorization of “super corals”. This success was due to the strong collaboration and support from scientists of University of Mauritius that stimulated the exchange of knowledge and experiences. We had also accomplished one of the most important requirements of this Kakenhi in educating and training young scientists: two recent post-doc. and 5 graduated students joint the research team.
Moreover, we held a joint workshop at UoM titled “Winners and Losers on Coral Reefs in the wake of Climate Change” (WLCRCC-2019) on March 15. More than 100 participants attended the workshop, including university authorities (University Dean and the Vice councilor for Academia), stakeholders, members of The Biodiversity and Environment Institute and graduate students. All of our research members offered 40 minutes oral presentations and we also held a panel discussion at the end of the workshop with participation of the audience. We were also interviewed by Mauritius national TV channel and one prestigious newspaper.
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| Strategy for Future Research Activity |
2019: physiological responses of corals under normal vs. elevated seawater temperature and light. (a) Continuing surveys in the two selected reefs. (b) Evaluation of coral physiological responses using incubation experiments under normal vs. stressful conditions of temperature and light with (3-4 days), and posterior recovery (4-6 days). Coral nubbins under normal (ambient) and stressful temperatures (plus 2 to 4 °C) and light (over 1500 micromol cm-2 sec-1) will be incubated to evaluate their responses in the reduction of oxidative stress, reduce apoptosis, defense against infections, feeding capacities under normal or bleached conditions. We will test posterior recovery capacity, by placing the corals back to ambient conditions. Experiments will be done in collaboration with UoM research team. Incubation experiments will be developing at incubation facilities of Albion Fisheries Research Centre, and UoM laboratory facilities. (c) Similar incubations will be performed to measure coral grazing rates on plankton collected in the same reefs. (d) We will hold the second workshop at UoM
2020: summary, conclusions and recommendations. (a) Continuing taking data from incubation experiments. (b) Create a first molecular genetic catalogue/database for Symbiodinium from corals of Mauritius. (c) Summary of data with characterization of a “super coral” and identification of such areas in Mauritius that can provide “super corals” for the future of African Reefs (d) Make relevant recommendations for inclusion of areas bearing “super corals” in Marine Protected Areas
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| Causes of Carryover |
モーリシャスにおいて、現地調査の補助としてモーリシャス大学の学生を雇い、謝金を支払ったが、現地状況に合わせて作業内容を検討した結果、謝金の金額が当初想定していたよりも安くなった。また、モーリシャスにおける調査のための船舶使用費が当初の計画よりも安く済んだことが次年度使用額が生じた理由である。
翌年度の使用計画として、今回の調査・分析および調査に関わる移動において破損した物品（物品収納用のプラスチックコンテナ容器・ガラス製実験機器等）などの購入・修理等に充てる予定。
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Research Products
(13 results)
