An Encrusting Hard Coral Enclosing Soft Coral in the High-Latitude Asia–Pacific Marginal Distribution Zone

Abstract

Environmentally adapted and resistant hard and soft coral communities within the high-latitude Asia–Pacific marginal distribution zone are thriving, despite their comparably stressful environment (unfavorable winter water temperature and light regimes). Korea’s Jeju Island is famous for its diverse and abundant soft coral communities, which coexist with reef-building hard corals. Although antagonistic interactions between soft and hard corals generally feature the soft coral as the winner, we observed a soft coral of the species Dendronephthya gigantea completely enclosed by the encrusting hard coral Montipora millepora accompanied by a general decrease in soft coral and increase in M. millepora abundances. This indicates an ongoing species/habitat shift with significant impacts on the current state of corals living at their geographic limit.