The phytoplankton and macrophytes are the main primary producers in the ecosystem of Tonle Sap Lake (TSL). The average biomasses of the phytoplankton and macrophytes in TSL were estimated at 5.48 ton/km2 and 1489 ton/km2, with the ratios of production to biomass being 185/year and 1.67/year, respectively. Blue-green algae dominate during the low-water period when the lake water is highly turbid, and the dominant taxa shift to diatoms during the high-water period when the water is relatively transparent. A survey in 2017–2019 indicated that the concentration of planktonic Chl-a in the surface layer varied seasonally and spatially, and its concentration was higher in the low-water period (March and June) than in other periods. The net primary productivity in TSL is estimated to be 2.0 g-C/m2/day or 2.5 × 106 ton-C/year. The primary production in TSL is considered to be effectively channeled through the food web, resulting in the remarkably high fish production. Based on a crude estimate of fish harvest and a wide range of possible fish harvest, the fisheries harvest is estimated to be equivalent to 7–69% of the total aquatic net primary production in the lake.
各種検索
サポート
ヘルプ