BEIJING, May 31 (Xinhua) -- China made solid steps in 2018 toward the goals of ecology and environment under the 13th Five-Year Plan (2016-2020), according to a recent communique.

The country's ecological and environmental quality improved continuously last year, with pollutant discharge and carbon dioxide emissions being further reduced, said the communique issued by the Ministry of Ecology and Environment (MEE).

County-level areas with good air quality accounted for 44.7 percent of the country's total land size, up 2.7 percent year on year, while carbon dioxide emissions per unit of GDP dropped about 4 percent, 0.1 percentage points higher than the annual target.

Some 338 cities enjoyed more good air in 2018, with average number of good air quality days up 1.3 percentage points and the density of PM2.5 declining 9.3 percent from the previous year.

The Beijing-Tianjin-Hebei region reported good air quality on 50.5 percent of days, up 1.2 percentage points from one year earlier, while the share of good air quality days in the Yangtze-River Delta increased 2.5 percentage points to 74.1 percent.

Water quality also improved last year, seeing an increase of 3.1 percentage points in surface water cross sections categorized as good-quality.

The MEE also reported a notable improvement in the marine ecosystem and environment. Inshore waters of good quality accounted for 74.6 percent, up 6.7 percentage points from 2017.

Sea areas with the highest level of water quality expanded by about 20,000 sq km last summer, MEE data showed.

Bai Qiuyong, an official with the ministry, attributed such improvement to the country's effective measures on protecting marine ecosystem and environment.

According to the 13th Five-Year Plan, China aims to see a more than 80-percent annual average share of good quality days by 2020, and improve the share of surface water of the third quality level or higher to at least 70 percent.

To achieve such ecological and environmental targets, the central government provided fiscal support worth 255.5 billion yuan (about 37.03 billion U.S. dollars) in 2018.

China should continue its tough battle against pollution and seek further improvement of ecological and environment quality, Bai said.