摘要
1．越冬池底层水温一般为1-3．5℃，2月份最低(平均1．03℃)。采用扬水曝气，水温低于0．5℃。2．明冰下的光照达数千以至上万1x的一般一天有6—7小时以上。乌冰下的光照亦可达3×10^31x以上，仍有较大的产氧潜力。3．明冰下的光合作用日产氧量为0．21—12．45，平均2．34±2．11毫克氧／升·日。补偿深度平均为1．13±0．35米。底泥耗氧率平均为0．40克／米^2·日；水呼吸耗氧率为0．04—3．76，平均0．62±0．52毫克／升·日。4．铵氮各池平均值在0．05—1．29毫克／升总平均0．19(1979年)及0．54(1980年)。硝酸氮各池平均值多在0．1毫克／升以下。亚硝酸氮含量很低，最高0．0137平均0．0027毫克／升。磷酸盐含量平均为0．049(1979年)和0．040(1980年)毫克P／升。5．发现了冰下表层有对藻类的光抑制和营养盐对光合作用的限制现象。试用冰下施无机肥以提高光合作用速率，效果很好。
This paper presents the results of investigation on the physical and chemical conditions of overwintering fishponds in northeastern China. They may be summarized as follows:1. The bottom water temperatures usually ranged 1—3.5℃ The minimum value (1.03℃) occurred in February. The water temperatures in ponds that were aerated by means of pumping tended to be lower than 0.5℃.2. Under clear ice the period at which the illumination intensities reach several to even more than ten thousands lux lasts 6—7 hrs. a day. Under turbid ice the maximum illumination intensity may also reach 3,000 lux, so there is still a large potentiality of oxygen production under such condition.3. The gross photosynthesis under clear ice is 2.34±2.11 (0.21—12.45)mgO_2/l.d. The compensation depth averages 1.13±0.3m. The oxygen consumptions of botton mud and of pond-water due to respiration average 0.40 and 0.62±0.52 (0.04—3.76) mg/l. respectively.4. The mean contents of ammonia in the pounds range 0.05—1.29 mg/l. The average total contents of ammonia in 1979 and 1980 were measured to be 0.19 and 0.54 mg/l respectively. The average contents of nitrate are usually not more than 0.10 mg/1. The contents of nitrite are very low, being 0.013 mg/l in maximum and 0.0027 in average. The contents of phosphate in 1979 and 1980 were 0.049 and 0.040 mg P/L respectively.5. The rate of photosynthesis under ice is increasable when applying inorganic fertilizer.In addition to results given above the optimum depth and the management technology of water quality are discussed in this paper. The phenomena of light inhibition under the ice and the restriction of carbon dioxide and nutrient salts to the photosynthesis are also mentioned.
