On a blazing hot Tokyo summer day, children squeal with delight as they splash about on a sandy beach, with the skyline of the world’s biggest city shimmering behind them.
The scene may seem unremarkable but it was unthinkable until recently when local activists decided to clean up the polluted water at city beaches, hoping to leave a legacy from the Tokyo 2020 Olympic Games.
“Tokyo Bay used to have many swimmable beaches,” recalls one of these activists, 70-year-old Yuzo Sekiguchi. “But by the time the last Tokyo Olympic Games were held in 1964… the water was polluted by factory effluent.”
“I decided to bring back clean Tokyo beaches for the next generation,” he told AFP.
Sekiguchi, whose ancestors fished these waters for generations, used natural elements like seaweed and oysters to purify the waters at a section of the beach in Tokyo Bay, which faces the vast Japanese capital.
“Each oyster can purify 400 litres (105 US gallons) of water every day,” he said.
The oysters gobble plankton and absorb bacteria, making the water clearer and cleaner. They remain edible though authorities don’t recommend consuming them thanks to the bacteria content.
The stretch of shore that Sekiguchi has been cleaning up first opened for swimmers in 2012, initially for just a few days as an experiment.
But it has been available to swimmers almost all summer round since 2015. This year it is open for 42 days, thanks to popular demand — a week longer than in 2017.
Each year, authorities test the water quality before giving permission for swimming at the beaches. And while Sekiguchi decided to start the clean-up work on his own initiative, he has since received backing, including financial support, from the local government.
