The ecological restoration of lakes on the Erhai Plateau of Dianchi Lake has achieved results Sea cauliflower has bloomed in Dianchi Lake

Professor Kong Hainan of the College of Science and Engineering introduced the experience and effectiveness of ecological restoration of Lakes in Kunming Dianchi Lake and Erhai Plateau. Both experts mentioned that after ecological restoration, the water quality becomes better and the sea cauliflower blooms into beautiful flowers.

Sea cauliflower opening in the Erhai Sea, Yunnan Province (photo taken on May 31, 2020) Photo by Jiang Wenyao, Xinhua News Agency

Vegetation coverage of wetlands around Dianchi Lake

From 13.1% in 2007 to about 81%

"Baofeng Wetland is a typical example of our team's restoration of plateau lakes." Yang Junxing, a researcher at the Kunming Institute of Zoology of the Chinese Academy of Sciences, said frankly that at present, the lakeside ecosystem of Dianchi Lake has been initially restored, the ecological status has continued to improve, the biodiversity has been enriched, the vegetation coverage rate of the wetland around Dianchi Lake has increased from 13.1% in 2007 to about 81% now, the plant species have increased from 232 to 303 species, and the birds and fish that have disappeared in Dianchi Lake for many years have reappeared. Among them, after the water quality became better, the sea cauliflower has bloomed in Dianchi Lake.

Yang Junxing introduced that there are 594 species of indigenous fish in Yunnan, accounting for 37.5% of the number of freshwater fish species in the country, ranking first among all provinces in the country. Fish diversity has declined since the 1960s, especially in highland lakes, where endangered species account for more than 60 per cent of indigenous fish species in lakes. In view of the severe situation of the protection of indigenous fish in Yunnan, Yang Junxing's team has been committed to the research on the conservation and sustainable use of indigenous fish, at present, 102 species of indigenous fish in Yunnan are preserved in situ, 48 species of artificial breeding technology are broken, and 3 species of industrialization have been initially realized, including Dianchi lake golden ray catfish, catfish whitefish and soft-finned fresh lip fish.

Taking the Dianchi Lake golden line catfish as an example, the Dianchi lake golden line catfish was once the main catch object of fishermen along the Dianchi Lake, and the production was quite abundant, since the 1960s, due to various factors, the number of dianchi golden line catfish has decreased sharply. By the end of the last century, its Lake in Dianchi had basically disappeared, and only a very small number of populations remained in the surrounding rivers and Longtan. In 1989, the Dianchi lake catfish was listed as a national class II protected animal, and in 2008 it was declared critically endangered by the IUCN Red List. Since 2000, Yang Junxing's team has begun to study the number, distribution, habitat, feeding ecology and breeding ecology of the Dianchi lake golden ray in the basin, carried out wild introduction and artificial domestication in 2004, successfully artificial breeding in 2007, and then carried out breeding and stocking studies to restore its wild population. So far, more than 2 million Dianchi golden-line catfish have been added and released to the Dianchi Lake Basin, and the evaluation results of the breeding and stocking effect show that the Dianchi lake golden-threaded catfish has formed a stable population in the Panlong River, and the growth and development are in good condition.

Based on this, the "flower-fish-snail-bird" three-dimensional ecological restoration model of indigenous organisms to restore the ecosystem was innovatively proposed, and ecological restoration demonstrations were carried out in plateau lakes such as Dianchi Lake, Erhai And Qilu Lake, and good ecological, economic and social benefits were achieved. On January 20, 2020, general secretary Xi Jinping inspected Dianchi Lake and saw the "Dianchi Lake Ecological Tank" as one of them. At the same time, the sustainable use of Dianchi golden thread catfish was carried out, and after four consecutive generations of breeding, a new aquatic variety of Dianchi golden thread catfish with fast growth and weakening of intermuscular spines was cultivated - "Catfish You No. 1", which is the first new aquatic species in Yunnan Province and the first new variety created based on national protected fish in China. The approval of the Dianchi Golden Line Catfish "Catfish You No. 1" marks the success of the exploration of the Dianchi Lake Golden Line Catfish from conservation to sustainable use, and at the same time proves the feasibility of developing the characteristic fishery industry of the Yunnan Plateau represented by the Dianchi Lake Golden Line Catfish.

At present, it has authorized 23 invention patents for artificial breeding, bait and breeding of relevant fish, completed the research and development of the whole process artificial breeding technology system of 48 indigenous fish species, and increased and released more than 3 million indigenous fish species of 11 species to restore the wild population of rare and endemic fish. Now it has reached the capacity of producing more than 5 million indigenous fish fry per year, which can directly drive the annual output value of characteristic fish of more than 100 million yuan.

Construction of miniature Erhai at Shanghai Jiaotong University

Introduction of Dali "Two Flowers"

Kong Hainan, chief scientist of the National Water Pollution Control and Treatment Science and Technology Major Project and professor of the School of Environmental Science and Engineering of Shanghai Jiao Tong University, has spent an average of more than 200 days a year in the research station of Dali Erhai In Yunnan Province for more than 200 days in the past 20 years, leading the team to make unremitting efforts to tackle key problems, and finally let the Erhai Sea, which was seriously polluted due to overexploitation, return to the style of the "Mother Lake" in Dali in the past.

Kong Hainan received a bachelor's degree in environmental medicine from Tongji Medical University in 1983, and from 1988 to 2000, he worked as a researcher in the Water Environment Department of the National Institute of environmental research in Japan, during which time he pursued a doctorate in environmental engineering and carried out postdoctoral research. In 2000, when he was more than half a hundred years old, he resolutely decided to return to China to teach at Shanghai Jiao Tong University. After returning to China, Kong Hainan used his research and development technology in Japan and accumulated experience to participate in the comprehensive treatment and demonstration projects of rivers, lakes and reservoirs such as Taihu Lake, Chaohu Lake, West Lake, Erhai Lake, Dianchi Lake, Three Gorges of the Yangtze River, and Suzhou Creek. However, the most affected him was the Erhai Sea in Dali.

Since the 1990s, the Erhai Sea has long suffered from eutrophication of the lake, and the water quality of the lake has deteriorated sharply in two large-scale cyanobacteria outbreaks. The protection of the Erhai Sea has been included in the national "water pollution control and treatment" major scientific and technological projects.

In 2006, kong Hainan was 58 years old when the Erhai project was launched, but he resolutely chose to be the project leader considering that the State Council had approved the expert proposals, including his own, and set up the "National Water Pollution Control and Control Major Special Project". In May 2012, the Erhai project entered the acceptance stage, and he suffered from heart disease until the end of the project acceptance in September of that year, and then urgently returned to Shanghai for two consecutive large surgeries.

For more than 10 years, the team of Shanghai Jiaotong University has more than 1,000 teachers and students stationed in the front line of river and lake governance such as Erhai, and more than 20 teachers and students have been conducting field research in Dali and other places all year round, completing more than 30,000 field sample collections and analyzing water quality indicators more than 160,000 times.

On October 24, 2019, Kong Hainan, witnessed by the Education Development Foundation of Shanghai Jiao Tong University and the relevant person in charge of the School of Environmental Science and Engineering, generously donated 2 million yuan to inject the first fund into the Shanghai Jiaotong University Erhai Protection Talent Education Fund.

In this battle to defend the Erhai Sea, Kong Hainan and his team joined hands with dozens of units such as the Chinese Academy of Environmental Sciences, the Institute of Hydrobiology of the Chinese Academy of Sciences, and the Chinese Academy of Agricultural Sciences to use more than 10 years to make the water quality of the Erhai Sea from turbid to clear, and maintained the national Class II and III water quality standards for 3 consecutive years. With the gradual recovery of ecology, Erhai specialties such as Dali carp and sea cauliflower, which have disappeared for many years, have disappeared again, and even new species of birds that have never stayed in the Erhai Sea have emerged.

"I am 74 years old, but considering that the Erhai project needs to be followed up, I introduced 200 Yunnan cherry blossoms unique to Nanjian to Shanghai Jiaotong University, and at the same time transplanted the sea cauliflower flowers from the Erhai Sea to Shanghai Jiaotong University, built a miniature Erhai Sea, modeled on the climate of the Erhai Sea and other methods of planting, and now it is growing well." I'm older, but there are a lot of young 'water people' on the team who will continue to work and will do better. ”

Source: City Times all-media reporter Pang Jiguang

Edit: Tang Wei