Hanoi’s iconic Hoan Kiem Lake has been severely polluted through the years and must be cleaned to save the threatened living creatures there, experts said. (Photo: Bizlive)

Hanoi (VNA) - Hanoi’s iconic Hoan Kiem Lake has been severely polluted through the years and must be cleaned to save the threatened living creatures there, experts said.

Hoang Thi Thu Huong, Deputy Director of the Institute for Environmental Science and Technology under the Hanoi University of Technology, said the lake was contaminated and had lost the ability to clean itself.

The thick mud at the bottom of the lake contains heavy metals and toxic gases, affecting the habitats of creatures, she was quoted as saying by Kinh te va do thi (Economic and Urban affairs) newspaper.

The high density of algae means there is not enough oxygen and dredging work is a must to protect the lake’s ecosystem and restore its beauty, she said at a public consultation on the environmental impact assessment report conducted by her institute, co-organised by the Hanoi Sewage and Drainage Ltd and the People’s Committee of Hoan Kiem district.

While most scientists and residents living in the areas around the capital’s central pivot agreed on the need to improve the lake’s water quality, scientists said the environmental improvement plans for the lake should be conducted prudently to redress its pollution while protecting its ecosystem and biodiversity.

Duong Duc Tien, a biological expert, said the process of rehabilitation and dredging must be carefully considered to make sure it does not badly affect the lake’s habitats. The types of fish and algae living in the lake mist be catalogued in detail, he added.

Mai Dinh Yen, another expert, agreed, saying mud layers should be maintained during the dredging process since it is the habitat for many species.

Nguyen Ngoc Ly, director of the Centre for Environment and Community Research, proposed that Hoan Kiem district set forth regulations to prevent residents from releasing fish into the lake. "Hoan Kiem Lake has many kinds of alien species. Some people even bring sacks of eel and snails to the lake," she said.

Trinh Dang Khoa, who resides on Dinh Tien Hoang Street, said that despite efforts in recent years to improve the lake’s water quality, the results did not meet residents’ expectations.

Nguyen Thi Minh Ha, chairwoman of the Ly Thai To Fatherland Front, stressed the need to raise the awareness of local residents to the lake’s ecosystem protection.

Phan Hoai Minh, Deputy General Director of Hanoi Sewage and Drainage Ltd, the cleanup project’s investor, said the company will instruct the consultants to review all suggestions, particularly those on biodiversity in the environmental impact assessment. Once completed, the report will be submitted to the scientific council at ministerial and municipal level for approval.

Covering about 12 ha, Hoan Kiem Lake (also known as Returned Sword Lake) is located in the centre of the capital. Apart from its spiritual and cultural values, it is considered a scenic venue, a hub for weekend relaxation from the chaos and bustle of the city.-VNA