Ahead of the planned release of treated radioactive water from the Fukushima nuclear power plant, Hong Kong and mainland China — Japan’s top two seafood export destinations — are saying no to once-sought-after food products from Japan.

“As a preventive measure, once Japan discharges the wastewater into the sea, the Hong Kong city government will immediately ban all aquatic products from 10 prefectures in Japan,” the Hong Kong government said Wednesday.

The import ban from Japan’s two biggest seafood buyers will deal a significant blow to local fishing industries, which were already grappling with the repercussions of the March 2011 triple-meltdown disaster at the Fukushima No. 1 plant.