A Japanese Olympic venue was overrun by oysters, leading to $1.28 million in repairs

• Japan removed 14 tons of oysters from wave-blocking barriers at a Tokyo Olympics 2020 venue.
• The barriers unexpectedly sunk in mid-2019 right after the course was constructed.
• The cleanup cost officials 140 million yen, or $1.28 million USD.

An upcoming Tokyo Olympic venue needed $1.28 million in emergency repairs in September due to an onslaught of oysters.

Olympic rowing and canoe sprinting is set to be held at the Sea Forest Waterway in Tokyo Bay, a location built specifically for the 2020 Summer Olympics and Paralympic Games.

Japanese workers placed floating barriers around the water to prevent waves from hitting the athletes mid-row, but two-thirds of the floats unexpectedly sank after 14 tons of oysters attached themselves to the barriers. According to Kyodo News, the oysters thrive in the unique high-salinity water and local phytoplankton conditions in the Sea Forest Waterway.

The Sea Forest Waterway is located in a region that was formerly home to several seaweed farms and fishing grounds and a large oyster reef sits just five kilometers from the Olympic venue. Despite being a local delicacy, officials told The Asashi Shimbun the oysters discovered were not eaten.

"We did not consider consuming them," the official said. "That would entail safety checks. More important is that we do not want to grow oysters but work to contain them."

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Japanese officials said they don't expect the oysters to affect the upcoming games as the current floating barriers were placed after the time when young oysters attach themselves to a solid surface, though they said they expect to spend 160 million yen per year, or $1.46 million USD, on upkeep for the Sea Forest Waterway.

The waterway will be used for the Paralympic Games in August 2021 and as a venue for future watersports competitions in the region. The Asashi Shimbun said local officials are considering electrolyzing the seawater to try and stop the oysters from returning in the future.

The Sea Forest Waterway's first Olympic event is set for July 22 for single, double, and quadruple sculls heats. The opening ceremony is scheduled one day later on July 23.