Sea ice off China's east coast, the worst in 40 years, has caused more than 1 billion yuan (about 146 million U.S.dollars) of losses to the fishing industry in Shandong Province, the provincial marine and fishery department said Thursday.

The ice closed 16 fishing harbors, trapped nearly 4,000 fishing boats and caused the loss of 100,873 tonnes of fishery products, the department said.

The ice is set to worsen, it added.

The sea ice appeared early January along the coasts of the Bohai Sea and the Yellow Sea as cold fronts pushed temperatures below minus 10 degrees Celsius, according to the National Marine Forecasting Station.

The ice has also affected marine transport, fishing, aquatic breeding and offshore mining in northeast China's Liaoning Province, north China's Hebei Province and Tianjin Municipality.

The Shandong provincial marine and fishery department has sent work groups to help fishermen with disaster alleviation.