China has seen its mangrove forests significantly expand since the start of the new millennium, as the country undergoes consistent improvement in its marine environment, the Ministry of Ecology and Environment said.

As of 2022, China had 29,200 hectares of mangrove forests, up by 7,200 hectares from the beginning of this century, said Hu Songqin, deputy director of the ministry's Department of Marine Ecology and Environment.

"This has made China one of the few countries in the world with a net increase in the size of mangrove forests," she told a news conference on Monday.

Mangrove forests are an important marine ecosystem that play a significant role in purifying seawater, preventing wind and waves, maintaining biodiversity, and storing carbon, she said.

"President Xi Jinping attaches high importance to mangrove conservation and has issued directives about mangrove protection for multiple times, stressing that the mangroves are a national treasure," Hu said.

Xi, for instance, inspected the mangrove area on Jinniu Island in Zhanjiang city, Guangdong province, in April. He said mangroves should be protected the same way we protect our eyes.

Hu outlined a series of measures to enhance mangrove conservation, as the ministry strives to implement Xi's instructions.

The ministry will continue to step up mangrove protection with the help of "Green Shield", a national inspection campaign that cracks down on violations in protected areas, and also by intensifying satellite monitoring of human activities, she said.

It will also evaluate and assess mangrove protection measures as part of efforts to further improve the effectiveness of conservation work, she added.

The health of mangrove ecosystems will be a priority for the ministry, she said. Greater efforts will be made to gradually bring more mangrove forests under its monitoring, and the heath of all typical mangrove ecosystems across the country will be evaluated on a regular basis.

Liu Dejun, a spokesman for the China Coast Guard, said regular patrols of mangrove areas have been ramped up to better protect ecosystems and help the country reach its climate targets.

China aims to peak carbon dioxide emissions before 2030 and realize carbon neutrality before 2060.

As one of the top carbon-capturing ecosystems on Earth, mangroves can sequester carbon dioxide at a much more efficient rate than most comparable ecosystems.

Making use of video surveillance, drones and satellite remote sensing to facilitate its monitoring work, China Coast Guard has uncovered six violations that concern mangrove protection in recent years, including illegal logging of mangroves and illegal occupation of mangrove areas, Liu said.

According to the Ministry of Ecology and Environment, the quality of seawater in 81.9 percent of the country's shore areas reached Grade II or Grade I in 2022, up by 0.6 percentage points year-on-year.

China has a four-tier system for the quality of seawater, with Grade I the best.

The country has eradicated unhealthy marine ecosystems since 2021, the ministry said.