山东省大、中型水库鲢、鳙的生长与环境条件的关系

根据1989年的调查资料,研究了山东省20座大、中型水库鲢、鳙的生长与环境条件的关系。将进水量、集雨区土壤肥力、总氮、总磷、硬度、电导率、化学耗氧量、浮游植物生物量、浮游动物生物量等9项标志水域鱼产力的环境条件,分成基础条件(指前二项)、化学条件和生物条件三个层次分别考查其与鲢、鳙的生长关系。提出的这三个层次都对生长有显著影响,达到或接近于强相关。通过逐步回归得出的复回归模式则更表明生长与这些条件的相关高度显著。指出在像当前山东省大多数水库这样,鱼的密度显著小的情况下,鱼的生长情况可以作为概略评价水域鱼产力的一个相对指标。

ON THE RELATIONS BETWEEN THE GROWTH OF SILVER CARP AND BIGHEAD CARP AND THE ENVIRONMENAL FACTORS IN LARGE AND MEDIUM SIZED RESERVOIRS IN SHANDONG PROVINCE

The relatons between the growth of silver carp and bighead carp and the environmental factors in twenty large and medium sized reservoirs in Shandong Province were examined on the basis of the survey conducted in 1989. Nine factors indicating fish productivity of the reservoirs, including the volume of annual inflow of water, the soil fertility in the catchment area, total nitrogen, total phosphorus, hardness, electric conductivity, chemical oxygen demand, and the biomass of phytoplankton and of zooplankton, classified into three gradations, i. e. the basic, the chemical and the biological gradation, were examined on their relations with fish growth. It was found that each of the three gradations of factors affects fish growth prominently, their correlations with the latter near or attain the "strong" level. The multiple regression models formed through progressive regression even show that the correlations are highly signifieant (R = 0. 844 and 0. 823). Based on these results the authors suggest that when fishes are sparsely populated in certain waters fish -growth may serve as an index for evaluating the relative fish productivity of these waters.