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Water hyacinth helps control Dianchi Lake pollution

By : InKunming|Updated: 2011-10-20

Water hyacinth is reared in controlled captive conditions in the watershed of Dianchi Lake. [Photo/Wang Junxing]

Water hyacinth has helped control pollution in the Dianchi Lake. Accoding to the related scientific research group, after nearly half–a-year observation and sampling analysis, preliminary result shows: Caohai Lake does not blacken and stink.

Water hyacinth is reared in controlled captive conditions in Caohai Lake, the most seriously polluted area in Dianchi Lake. A total of 13.12 square kilometers of water hyacinth has been reared in controlled captive conditions in the watershed of Dianchi Lake by October 17, 2011. A scientific research team studying Caohai Lake has been established for monitoring and assessing how the water hyacinth influences the water quality of Dianchi Lake.

No harmful ecological hidden problem has been found in Caohai Lake. By now, 300 thousand tons of water hyacinth have been reared in Caohai Lake, covering 80% of the total area. The PH value and dissolved oxygen of the water-body has not changed much. The water-body is more transparent. The height of water-body transparency in parts of watershed has reached 1.9 meters, which is quite beneficial for the growth of submerged plants. There are not huge numbers of dead fishes. Ceratium hinundinella, which are usually seen in Dianchi Lake in the 1950s, have reappeared.

According to the preliminary result, in recent years, the quality of Caohai Lake is better. Total phosphate and nitrogen in the water shows decline trend. Especially in 2011, the improvement of the water quality is more obvious. Compared to the beginning of the period of 11th Five Year Plan (2006-2010), the total phosphate and nitrogen in September 2011 has respectively reduced by 73% and 80%. The main eutrophication index has noticeably reduced.

According to a vice director of Ecological Research Institute of Dianchi Lake, Han Yaping (韩亚平), the institute will pay much attention to the water quality and aquatic ecological community succession tendency during the period of water hyacinth picking. Meanwhile, the monitoring data of related rivers and lakes will be sorted, to understand how water hyacinth influces water of Caohai Lake and aquatic ecology fully. (Editor:Tina He)

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