The seabed turned white. A fisherman refused to accept it.
Along Japan's coasts, warming seas and exploding sea urchin populations are stripping the seabed of seaweed — a phenomenon called isoyake, or "coastal burn-off." The seaweed forest is the base of the whole coastal food web: fish spawn and grow in it, squid lay their eggs on it, abalone, turban shells and sea urchins feed on it. Lose the forest and you lose the nursery, the carbon sink, and — eventually — much of what ends up on a sushi counter. In Kushiura, Karatsu, diver Shozo Kesamaru decided to bring the forest back himself.
A seabed with no seaweed.
Long-spined Diadema urchins — a species spreading with warming seas — and overabundant purple urchins graze every new sprout before it can grow. The rock turns white. The fish and shellfish leave, and the edible urchins themselves are starving — hollow shells with no uni inside.
Diving to restore the balance.
Divers thin the urchins by hand — removing Diadema and excess purple urchins — plant seaweed, and test artificial reefs. It is physical, repetitive, underwater work — and it only works if it continues year after year.
The forest comes back. So does life.
Restored beds bring back the fish, the squid, the shellfish — and the carbon-absorbing forest. No farming, no fattening: the urchins are wild, and a balanced seaweed forest is what gives them their flavor. The sea feeds people again.
