Standing Crops and Temporal and Spatial Distribution of Corbicula Fluminea in An Aquaculture Lake (Datong) in the Central Yangtze Basin

Datong Lake is the largest lake for aquaculture in Hunan province, which is also one of the typical shallow lakes in the Central Yangtze River Basin. To achieve sustainable usage of C. fluminea, the present study investigated standing crops and temporal and spatial distribution of C. fluminea in the Datong Lake during 2009-2011. Mean (± SE) density and biomass of C. fluminea increased significantly from 2009 (90 ± 18 ind./m², 272.9 ± 50.2 g/m²) to 2010 (502 ± 67 ind./m², 394.7 ± 40.1 g/m²) and 2011 (277 ± 34 ind./m², 447.2 ± 48.7 g/m²). In 2009, C. fluminea were mainly distributed in the central and north part of the Datong Lake, the area of the sub-lake Mifengjia Lake. After 2010,the distribution of C. fluminea extended significantly and occupied almost the whole lake, which showed a decreasing pattern from the northeast to southwest. Higher density and biomass mainly occurred at the interaction zone of three sub-lakes. The results suggested that physical and chemical inputs resulting from aquaculture was possibly one of the main reasons for the increase of C. fluminea standing crops and affected their distribution in the Lake.