tiny relatives of crabs and shrimp that are known in the region as nanatsuba-kotsubumushi, are boring into the uninhabited island of Hoboro

Recent rises in ocean temperature have led to an increase in the amount of plankton in the protected waters around the island

Plankton are a staple of the nanatsuba-kotsubumushi, and the abundance of food has led to a surge in the crustaceans

"The creatures make holes in the rock as they make nesting areas," Okimura said, "which makes it weaker and very susceptible to weathering from the ocean and the wind."

In a survey carried out in 1928, Hoboro was recorded as being 390 feet (120 meters) long and standing nearly 72 feet (22 meters) above sea level at its highest point

All that remains today, however, is a rocky promontory about 20 feet (6 meters) high at the western end—and that is almost covered at high tide

Hiroshima residents living nearby first noted that the island seemed to be getting smaller after every storm or typhoon