Frozen seas off the coast of China are expected to expand to severe levels in late January, posing threats to offshore oil and gas fields, leaving thousands of ships stranded and affecting aquaculture farms.

"Although the temperature has stopped decreasing, sea ice has been continuing to grow," Zhang Qiwen, a sea ice expert at the National Marine Environmental Forecasting Center, told China Daily on Tuesday.

The peak of this year's sea ice may be similar to the level in 2010 when about 90 percent of Bohai Bay was covered by ice, the worst freeze in the bay in the past 30 years, according to Zhang.