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Freshwater Ecosystem Conservation in Hainan

Yinggeling National Nature Reserve (YGL), in Hainan, has the most extensive tropical rainforest in South China, and is an important watershed for the two largest drainage basins in Hainan – the Nandu River and Changhua River. The communities around YGL are blessed with the rivers' rich aquatic resources, which provide them with potable and irrigation water, and feed them with animal protein in the abundant fish life.

But over the years, the river health has been deteriorating: pollution by farming chemicals and organic wastes, erosion by expanding farmland, impoundment for hydropower and irrigation, over-fishing, usually by destructive fishing practices such as dynamite fishing and poisoning, have decimated the fish population. Villagers report a sharp decline in most fish species, and the more sensitive species, such as the Red-faced Giant Barb (Spinibarbus denticulatus) are locally extinct.


In 2007, Kadoorie Conservation China Department (KCC) together with YGL started to encourage local communities to consider setting up their own village's fish no-catch zones to recover fish populations and increase catch outside these zones. We began the project in Daoyin Village, Baisha County. After lengthy discussions, Daoyin villagers selected the widest and deepest section of Nankai River with the highest fish concentration to be their Fish Sanctuary (FS) in 2008, governed by community rules and regulations.

We hosted a FS promotion workshop in Daoyin 2012 and reintroduced the extirpated Red-faced Giant Barb. The success of Daoyin FS has convinced more villagers to accept this novel conservation idea and a dozen or so FSs have been established around the Reserve. In addition, education programmes on fish and freshwater ecosystem conservation were held at nearby schools to raise awareness among the younger generations.


Constructed Wetland for Water Treatment and Wildlife Habitat

KCC and the Reserve had designed and built a constructed wetland to treat kitchen wastewater. A strainer made up the first stage treatment to filter out food residue in the sewage which can be used for composting. This also reduces the solids that flow into the septic tank. Manhole covered with double-lip seals was used in the septic tank to avoid mosquito breeding, which is found to be a major problem in many constructed wetland systems. Ornamental local plants filled the filter bed to absorb the pollutants in the wastewater, which also serves as a wildlife habitat.  The cleaned water is discharged to a polishing pond that serves as wildlife habitat. It is stocked with native fishes to control mosquito larvae. Moreover, as native stream fishes are sensitive to pollution, their health indicates that the system is working efficiently, This constructed wetland system has high practical value and could serve as an effective public education tool to instil environmental responsibility. The local topography was considered in the design to utilise gravity, avoiding the use of electric water pumps and saving energy. 


Read more:

1. Fish Sanctuaries Project in Yinggeling, Hainan