Characterization of Three Selected Macrophytes – An Ecological Engineering Approach for Effective Rehabilitation of Rawapening Lake

Rawapening is one of Indonesia’s national priority lakes, which is experiencing environmental damage and urgently needs rehabilitation. The decline in water quality is caused by sedimentation and organic and inorganic waste that triggers eutrophication. Rehabilitation of Lake Rawapening is important to improve the health of freshwater resources. The ecological engineering approach is the most appropriate choice to rehabilitate these water conditions. The character of the macrophyte is the key factor for successful rehabilitation. Three macrophytes, Hydrilla verticillata (L. f.) Royle, Eichhornia crassipes (Mart.) Solms and Salvinia molesta D.Mitch., charactierized. Their characteristics, including growth rate, salt tolerance, dissolved oxygen production and consumption, nutritive value, and preferred food by herbivore fish were evaluated. The results indicated that H. verticillata has the highest growth rate, is the most tolerant to salinity change, produces more oxygen, has the highest nutritive value, and is the most preferred food for herbivore fish. H. verticilata is recommended as the best candidate to be used as a forcing function to drive the Rawapening lake into more economic and environmentally valuable for a resident. As the other two species also have high nutritive value, they can be recommended as a source of feed for animals as well. For better management, these two macrophytes required more often regular removal. Other economic and environmental values can also be achieved from E. crassipes and S. molesta.