BEIJING, March 11 -- The majority of China's offshore sea areas have unhealthy ecosystems due to heavy pollution, a report from the State Oceanic Administration (SOA) has indicated.

Of the areas monitored by the SOA in the summer of 2014, 81 percent, or 41,000 sq km, was polluted. It said most of the polluted water was concentrated in river estuaries or sea bays. The main pollutants are inorganic nitrogen, reactive phosphate and oil.

The situation has only slightly improved from the previous year, when the SOA recorded 44,340 sq km of polluted sea waters.

What's more, the report said nearly half of the 445 major pollution discharge points along coastlines failed environmental requirements, greatly compromising water quality.

Marine disasters such as red tides and green algae also impacted larger sea areas in 2014 than in 2013, according to the report.