BEIJING - Half of China's 156 coastal outfalls are discharging excessive sewage into the ocean, according to the State Oceanic Administration.

According to a survey conducted by the administration in November, 78 ocean outfalls are discharging excessive sewage, with municipal drainage being the biggest contributor.

Survey results showed that South China's Guangxi is the most serious among six coastal provincial regions in over-discharging. Fourteen of its 15 ocean outfalls discharged excessive sewage.

The administration also said coastal erosion and soil salinization caused by saltwater intrusion have also worsened in China.

However, it added that it is optimistic about the environmental condition in marine dumping sites and oil exploitation areas as well as the situation regarding algal blooms.