Photo released on Oct. 23, 2020 shows Irrawaddy dolphins swimming in the Mekong River in Kratie province, northeast Cambodia. (WWF-Cambodia/Handout via Xinhua)

How happy they are! Irrawaddy dolphins are swimming and playing in the Mekong River in northeast Cambodia.

Critically endangered Irrawaddy dolphin is considered Cambodia's living national treasure. Its population in the Mekong River in Cambodia has been stable in the last four years, according to a new census conducted by the World Wildlife Fund (WWF) and the Fisheries Administration of Cambodia.

Photo released on Oct. 23, 2020 shows Irrawaddy dolphins swimming in the Mekong River in Kratie province, northeast Cambodia. (WWF-Cambodia/Handout via Xinhua)

Photo released on Oct. 23, 2020 shows an Irrawaddy dolphin swimming in the Mekong River in Kratie province, northeast Cambodia. (WWF-Cambodia/Handout via Xinhua)

Photo released on Oct. 23, 2020 shows Irrawaddy dolphins swimming in the Mekong River in Kratie province, northeast Cambodia. (WWF-Cambodia/Handout via Xinhua)