Cabbage diet for Japan's spiky sea urchins to help combat marine damage

While sea urchins naturally graze on marine plants, researchers have noted that their excessive numbers have contributed to the desertification of Kanagawa's coastline.

"There are a lot of sea urchins in the areas where seagrasses have disappeared," said researcher Shozo Takamura while carrying out a survey of sea urchin numbers.

"Divers and fishermen dive down in their bathing suits to collect and get rid of them, but their numbers have barely fallen so clearly there are a huge number of them."

Volunteer groups have been collecting the urchins, placing them in buckets and shipping them off to be used as fertiliser on local fields. But now the Kanagawa Fisheries Technology Centre is looking into a new use for the collected sea urchins that they believe could help support efforts to control the population.

"The urchins we're raising here at the research centre, which are Pacific purple sea urchins, really love vegetables like cabbage and komatsuna (Japanese mustard spinach), leafy vegetables basically," said researcher Yutaka Harada.

At the research centre located at the tip of Kanagawa's Miura peninsula, Harada tends to water tanks filled with sea urchins, feeding them cabbage and recording their growth.

The goal is to prove that sea urchins raised on a cabbage diet on land can attract buyers who will in turn fund further efforts to remove the sea urchins and restore the region's seagrass beds.

"We're working towards raising even tastier sea urchins on land and selling them to support our efforts against ocean desertification," Harada said.

Reuters