Increasing land-to-sea pollutants have led to further deterioration of offshore water quality.

The State Oceanic Administration (SOA) released a report on seawater quality for the first six months of this year on Friday in Beijing.

The report was based on more than 500 pollution outlets monitored by the SOA. About 77 percent of the outlets were discharging more pollutants than permitted, 18 percent more compared to last year.

The SOA report showed that every day 9,230 tons of land-sourced pollutants are pumped into offshore seawater, an increase of 6.7 percent over last year.

The pollutants were mostly chemical oxygen demands (COD), suspended matter, phosphate, ammonia and nitrogen.

The report covered more than 790 sq km of sea of which 453 sq km, 58 percent, was deemed to be bad, or seriously bad - not suitable for aqua farming, sea bathing, entertainment, or marine resources development projects.

"The surveillance is incomplete, in that it is not real-time, so the de facto seawater quality might be even worse than what the report says," Li Xiaoming, director of the marine environmental protection department of the SOA, said.

Improper distribution of pollution outlets is another problem, SOA spokesman, Li Chunxian, said.

Only 11 percent of waste had been discharged in designated areas while about 42 percent went into sea fishery farms. Others went into harbor areas and marine natural reserves.

Li Chunxian said that pollutants in the aqua farming areas led to further worsening of over-nutrition in the waters, however, it did not pose a threat to seafood security.

The SOA inspection showed that 35 percent of sea fishery farms were suitable for cultivation. The rest were relatively suitable.

Lin Shanqing, deputy director of the marine environmental protection department, said the improper distribution of pollution discharge outlets had a historical reason.

Although the country had begun to enforce its marine zoning management regulations, the outlet distribution map could not be improved in the short term.

Li Xiaoming said that reducing sea pollution needs the joint efforts of multiple departments, like the Ministry of Water Resources, Ministry of Construction and the State Environmental Protection Administration.

"Although the country had set a target of cutting 10 percent of pollution by 2010 from the level in 2005, a grace period is still needed," Li Xiaoming said. "Related departments have to work together."

Lin said the SOA will strengthen its monitoring of seawater quality and tighten the approvals of new marine projects.

Zhan Xiuwen, a professor at the marine environmental monitoring center, said: "It is not enough for each outlet to release the amount of pollutants permitted in order to improve sea water quality. China must control the total amount of pollutants into the sea."