长江口陈行水库悬浮物含量及鲢鳙放养量估算

2010年5月-2011年4月逐月对陈行水库悬浮物进行采样并分析其结构特征,根据水库悬浮物含量评估了水体的渔产潜力以及相应的鲢鳙合理放养量,并基于该水体浮游植物初级生产力的渔产潜力和鲢鳙放养量进行了比较,以期达到有效控制水库浮游植物数量的目的。结果显示,悬浮物年均总量(干重)为(29.4±7.3)mg/L,其中有机物占34.4%,灰分占65.6%。悬浮物总量表现为冬、夏季高,春、秋季低,悬浮物中有机物所占比例春、夏季高(分别占42.20%和41.70%),冬季低;相反,灰分所占比例冬季最高(达77.06%),夏季低。悬浮物干重的水平变动表现为St4采样点最高,出水口St1最低;悬浮物含量总体表现为沿水流方向呈逐渐减少的趋势。悬浮物干重的垂直水层变化表现为:4 m水层>表层>2 m水层>1 m水层>透明度0.4 m水层。采用悬浮物含量估算陈行水库滤食性鱼类的渔产潜力为37.32 t,可投放鲢15 400 kg,鳙560 kg。基于浮游植物初级生产力的陈行水库滤食性鱼类的渔产潜力为25.14 t,可投放鲢9 660 kg,鳙420 kg。

The distribution characteristics of suspended solids and the stocking of silver carp and bighead carp in Chenhang Reservior in Yangtze River Estuary

The suspended solids in Chenhang Reservoir were sampled monthly during May 2010 to April 2011 and their structural characteristics were analyzed.The filter fish production potentials and their reasonable stocking were evaluated,based on both the suspended solids concentration to control the abundance of phytoplankton in Chenhang Reservoir,and the primary phytoplankton production.Results showed: In Chenhang Reservoir the annual total amount of suspended solids(dry weight) was(29.4±7.3) mg/L,organic matter concentration accounted for 34.4% and ash content 65.6%.The seasonal changes showed the total suspended solids were high in winter and summer,low in spring and autumn.Organic matter concentration was high in spring and summer,occounting for respectively 42.20% and 41.70%,and low in winter;ash content accounted for 77.06% in winter while low in summer.As for the horizontal distribution of suspended solids in dry weight,the highest values occurred at St4,while the lowest value at St1 near outlet;Suspended solid was gradually reduced with the water flow direction.Vertical space change of suspended solid in dry weight showed that: 4 m water layer> surface> 2 m water layer> 1 m water layer> transparency 0.4 m of the water layer.Based on the suspended solids,production potentials of planktivorous fishes were predicted to be 37.32 t.Silver carp could be stocked 20 720 kg,bighead carp could be stocked 2 100 kg.However,based on phytoplankton primary production,the total planktivorous fishes production potential was 25.14 t,silver carp could be stocked 9 660 kg,bighead carp 420 kg.