7 - Lakes

Abstract

Indonesian lakes can be grouped into three major categories: built by volcanic action, fault lakes, landslide lakes, floodplain lakes, solution lakes, and coastal lakes. This chapter explores the varied state of Indonesian lakes. The most important functions of lakes inside of an environment can be grouped into three major categories: retention of water run off, habitat for specific flora and fauna, and source for human utilization. The ecological health of the larger natural lakes is still quite good. More than 77% of all lakes are dominated by exotic water plants such as Eichhornia crassipes, Salvinia molesta and Hydrilla verticillata. More than 90% of the major lakes have been stocked with exotic fish species such as Oreochromis sp. Lake management should be based on multiple objective and integrated planning with more emphasis on noneconomic objectives. It is necessary to identify and prioritize information and research needs, to monitor freshwaters, to establish ways to assess the quality of the lakes and to compile the existing information in database.