Ecklonia cava is a perennial brown alga and exists mainly in subtidal areas off the coast of Japan and Korea, especially in kelp forests along the central Pacific coast in Honshu (Southern Bōsō Peninsula/Chiba Prefecture to Wakayama Prefecture), parts of the Seto Inland Sea, the southern coast along the Sea of Japan, and the coast in Kyushu. The type locality is at Yokosuka, Kanagawa.
