Akashima Island
A natural water filter
The very small Akashima Island lies just off the east coast of Fukue Island. It gets its name, which means “red island,” from the reddish, oxidized volcanic ash that is ubiquitous here. The island is made of volcanic basalt, with a broad layer of newer, shallow volcanic ejecta around the shoreline. In the immediate area around the port is a series of mostly submerged basalt pillars, recognizable by their individual, crystalline shapes, although only their tops protrude from the ocean. The basalt makeup of the island, however, makes water sourcing a problem for its 10 current residents. Water percolates through the porous basalt without forming pools or streams, so the residents must collect rainwater for use. This motion of the water through the rock filters and cleans it; this pure water then flows into the ocean, attracting many fish and crustaceans, making this a popular fishing spot.