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鱼类在越冬期死亡原因是多方面的,主要有以下几方面。1.越冬水体严重缺氧。造成缺氧主要原因有:①池水清瘦,浮游植物数量少,光合作用弱,产氧少。②越冬水体有机物质过多,大量分解消耗氧气。③放养密度过大。④土壤保水力差,水位下降过大,鱼类活动空间减少。⑤污水流入,影响生长,造成死亡。2.鱼种小,体质差。鱼种规格小,体质差,体内积存脂肪等营养物质少,难以在漫长越冬期蓄积维持生存所需的能量,常因身体衰竭而死亡。又因鱼种体质差,在拉网作业中容易感染疾病而
There are many reasons for the death of fish during the winter, mainly in the following aspects. 1. The winter water serious hypoxia. The main causes of hypoxia are: â ’¢ thin water, less phytoplankton, photosynthesis is weak, less oxygen. ② overwintering water organic matter excessive decomposition of a large number of consumption of oxygen. ③ stocking density is too large. ④ poor soil water retention, water level dropped too large, reduced fish space activities. ⑤ sewage inflow, affecting growth, resulting in death. 2 small species, poor physical fitness. Small fish species, poor health, less fat and other nutrients accumulated in the body, it is difficult to accumulate in the long wintering period to survive the energy needed to survive, often due to body failure and death. Because of the poor quality of fish species, pull the net jobs easily infected with the disease