South Korea reported a year-on-year decrease in seafood imports from Japan in May for the second-straight month.

Local media outlets say this apparently reflects growing unease about Japan's plan to release treated and diluted water from the crippled Fukushima Daiichi nuclear power plant into the ocean.

The Korea Customs Service said fishery products imported from Japan in May were down roughly 30 percent from the same month a year earlier to 2,129 tons. This followed a year-on-year drop of about 26 percent in April to 1,736 tons.

South Korea's Yonhap news agency attributes the decline to growing public concerns about the Fukushima water release project.

Japan plans to release treated water after diluting it to reduce tritium levels to one-seventh of the World Health Organization's safety standards for drinking water.

South Korea's government has taken a range of steps to ease the public's concerns, including holding daily news conferences since last Thursday to give updates on the plan.

Last month, a South Korean group of experts visited Japan to learn about the project, which apparently has ramifications for other sectors of the South Korean economy.

A supermarket in Seoul says it is selling out of salt made from seawater. A staff member said this may be due to worried customers stocking up on salt before the release of treated water starts, to prepare for the annual kimchi making season, which requires a lot of salt.

The South Korean government has denied reports of people hoarding salt. Officials say South Korean-made salt is safe, stressing that they have never detected radioactive materials from salt in hundreds of tests conducted since the March 2011 Fukushima accident.