清河水库鲢、鳙鱼种群动态研究Ⅰ.生产量的估计

本文根据Robson-Chapman公式估算了清河水库鲢、鳙可捕群体的残存率,计算了非捕捞群体的残存率和种群生产量。清河水库非捕捞群体平均年残存率约为0.25,可捕群体的平均年残存率鲢为0.32、鳙为0.38。鲢、鳙鱼种群生产量分别为141和110kg/ha,种群年P/B系数分别为1.15和1.09。鲢、鳙鱼获量仅为其生产量的33%和34%,库存生物量的36%。

Dynamics of silver carp and bighead carp populations in Qinghe Reservoir I. Estimation of production.

The survival rates of catchable groups of silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) were calculated by means of Robson-Chapman formula, and those of noncatchable ones and population production were also estimated. The annual survival rates of noncatchable groups of the fishes were 0.25 in average, and those of catchable ones were 0.32 for silver carp and 0.38 for bighead carp. The total population production of silver carp and bighead carp was 141 and 110 kg/ha respectively. The yield of fishes was 33% and 34% of their production, and 36% of their biomass. The annual coefficients P/B of fish populations were 1.15 and 1.09 respectively.