[A-CG38] Coastal Ecosystems 2. Coral reefs, seagrass and macroalgal beds, and mangroves

[ACG38-P05] Seawater temperature fluctuation and coral distribution change in Temperate zone in Japan.

*Tomihiko Higuchi¹, Hatsumi Nishikawa¹ (1.Atmosphere and Ocean Research Institute, The University of Tokyo)

Keywords:Temperate zone coral, Kuroshio current, Meandering, Low temperature stress

The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. Coral distribution at high latitude in Japan places as northern limit of in the world. The presence of hermatypic corals at these high latitudes is due mainly to the strong Kuroshio current, which brings warm water. However, seawater temperatures in coastal areas, such as Kochi and Wakayama, experienced fluctuations due to Kuroshio meandering in 2017. Particularly, cold anomalies in seawater temperature were observed in January and February of 2018, leading to severe cold bleaching in Tosa Bay, Kochi (Leriorato and Nakamura, 2019). Conversely, the lowest seawater temperature in winter increased in the Boso area, Chiba, during these years. Stress response depends on the species and Acropora pruinose is one of strong specimen against cold temperature stress (Higuchi et al. 2015). We report a relationship between seawater fluctuation and coral distribution change in Temperate zone, mainly after Kuroshio meandering observed.

Reference:
Leriorato, J.C., Nakamura, Y. Unpredictable extreme cold events: a threat to range-shifting tropical reef fishes in temperate waters. Mar Biol 166, 110 (2019).
Higuchi T, Agostini S, Casareto BE, Suzuki Y, Yuyama I (2015) The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching. Sci Rep 5:18467.