Mesophotic Coral Ecosystems in the West Pacific: threatened ecosystems or hope for the reefs?

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06210
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: University of the Ryukyus
• Principal Investigator: Sinniger Frederic 琉球大学, 熱帯生物圏研究センター, ポスドク研究員 (10625940)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: Scleractinia

Outline of Final Research Achievements

This research revealed the differences in thermal thresholds of various mesophotic coral species by comparing them with shallow counterparts. Interestingly, while the absolute maximum temperature threshold was lower in mesophotic corals, these deeper coral could tolerate a higher level of thermal stress when measured in terms of difference from the temperatures they are used to (degree heating week). We also confirmed that Seriatopora, a model coral for the Deep reef refugia hypothesis, contained cryptic diversity, but this diversity is not related to the depth. The new development of this research was to expand to the coral triangle and we could show similarities in the Seriatopora genetic diversity between Okinawa and the Philippines, while Indonesia had a higher level of localised diversity within Seriatopora. Some genotypes present from Japan to Indonesia suggest that some of these corals may be able to survive the warming ocean in Okinawa.

Free Research Field

Biodiversity

Academic Significance and Societal Importance of the Research Achievements

This project showed the importance of the local adaptation of corals to their environment and finding the same species at different latitudes (or depths) does not means they can rapidly transfer from one location to the other.