Sea ice disasters and their impacts since 2000 in Laizhou Bay of Bohai Sea, China

Influenced by cold waves and low salinity of sea water, sea ice disasters occurred to Laizhou Bay frequently. The sea ice can be classified into five grades. Usually, sea ices of grade 3?C5 will have more or less impacts on beach shellfishes, mariculture and navigation. There was sea ice of grade 3 in normal winters, and there was sea ice of grade 4?C5 in cold winters. In the twentieth century, sea ice of grade 4 or 5 occurred five times in Laizhou Bay. During the years from 2000 to 2012, sea ice of grade 1 or 1.5 occurred twice, sea ice of grade 2 or 2.5, four times, that of grade 3 or 3.5, four times, and that of grade 4, twice. Among which, the sea ice disasters of 2009/2010 and 2010/2011 led to great damages and inflicted inferior impact on navigation, mariculture and marine organisms. To reduce the economic loss of sea ice disasters and their ecological influences, the authors put forward the countermeasures to sea ice disasters, which include strengthening the research of monitoring and forecasting of sea ice disasters, managing strictly the mariculture, establishing emergent recovery projects of sea ice disasters, constructing emergent recovery systems of sea ice and perfecting them continually.