Dozens of fishing vessels and ports have been damaged, with tonnes of the floating pebbles being removed from coastlines every day

Vast amounts of pumice pebbles, spewed out months ago by an undersea volcano, has clogged dozens of ports and damaged fishing boats along Japan’s southernmost coastlines.

Deputy chief cabinet secretary Yoshihiko Isozaki said on Friday that the pumice had so far affected 11 ports on Okinawa and 19 others in the Kagoshima prefecture, on Japan’s southernmost island of Kyushu, and forced the central government to establish a disaster recovery task force.