Seawater quality in the Bohai Sea has witnessed unprecedented improvement, an official with the Ministry of Ecology and Environment announced at a news conference on Thursday.

The proportion of water of "fairly good quality" reached 82.3 percent in 2020, 15.3 percentage points higher than in 2017, the year before a dedicated pollution control campaign was launched along the semi-enclosed sea, said Zhang Zhifeng, deputy head of the ministry's Department of Marine Ecology and Environment.

Under China's four-tier classification system for seawater, water quality is considered to be "fairly good" if it reaches Grade II or above.

Following a sharp increase from 2018, the proportion of such water was 77.9 percent at the end of 2019, according to a previous release from the ministry.

For the first time since monitoring began, Hebei province reported no seawater below the poorest quality of Grade IV last year, he continued.

"Thanks to coordinated pollution control efforts in the Bohai Sea region, there has been an unprecedented improvement along the shores," he said.

To curb pollution from land sources, the ministry identified 18,886 drainage exits along the Bohai Sea and enhanced monitoring and pollution control efforts at each, he said.