The restoration of aquatic macrophytes for improving water quality in a hypertrophic shallow lake in Hubei Province, China

This paper deals with a case study of the restoration of submerged macrophy tes for improving water quality in a hypertrophic shallow lake, Lake Donghu of Wuhan, Hubei Province, China. Macrophyte restoration experiments were c onducted in large-scale enclosures established in three sublakes of differe nt trophic status, and the effectiveness for water quality improvement was tested by using the enclosure experiment in the hypertrophic sublake. Water quality was remarkably improved after the reestablishment of aquatic macro phytes. It is suggested that the submerged vegetation of less polluted subl akes could be capable of recovering spontaneously once the stocking of herb ivorous fishes has been ceased, and the K-selected plants such as Potamoget on maackianus should be introduced into these sublakes to enhance the stabi lity of aquatic vegetation. However, it may not be possible and economical to restore the submerged macrophytes in severely polluted basins unless ext ernal pollution has been cut off and internal nutrient loadings considerabl y reduced. In this case, the r-selected submerged plants should be used as the pioneer species for macrophyte recovery. (C) 2001 Elsevier Science B.V. All rights reserved.