Deep-Water Macroid Beds of the Ryukyu Islands, Japan: Encrusting Acervulinids as Ecosystem Engineers

ABSTRACT Bassi, D.; Iryu, Y.; Humblet, M.; Matsuda, H.; Machiyama, H.; Sasaki, K.; Matsuda, S.; Arai, K., and Inoue, T., 2019. Deep-water macroid beds of the Ryukyu Islands, Japan: Encrusting acervulinids as ecosystem engineers. Journal of Coastal Research, 35(2), 463–466. Coconut Creek (Florida), ISSN 0749-0208. Encrusting acervulinid foraminifera can produce centimeter-sized, free-living coated grains named macroids. Macroid beds are an interesting feature of subtidal environments and have been recognized as important carbonate producers, habitat-forming structures, and paleoenvironmental indicators. Macroids provide a hard, three-dimensional substrate serving as microhabitat for a wide range of diverse organisms. As yet, the most extensive known occurrence of macroid beds in the western Pacific Ocean is found on the insular shelf of Kikai-jima, a coral reef–related island in the central Ryukyu Islands. The surveyed beds occur at water depth of 61–105 m arrayed on a ca. 6-km2 area. Despite their importa...