Studies on Mesophotic Coral Ecosystems in Japan

Abstract

In the last years, mesophotic coral ecosystems (MCEs) received increased attention from the research community. MCEs exist at depths between 30–40 m and until 100 m or deeper. While MCEs were already reported from Japan nearly 50 years ago, mesophotic research in Japan did not progress as in other countries like the USA or Australia. Nonetheless, over the years, several interesting studies were conducted on the MCEs found in southern Japan on various fields from geology to biology, and the momentum of Japanese mesophotic research increased in the recent years. In this chapter, we will summarize the knowledge on MCEs in Japan in different domains such as their distribution, their biodiversity, their occurrence in the fossil record, recent findings on the reproduction of mesophotic corals, their potential ecological role in a global change context, threats menacing these ecosystems, and future directions of MCE research in Japan.