河蟹生态养殖池塘溶解氧分布变化的研究

The research of dissolved oxygen distribution in the crab ecological culture ponds

在晴天、强风和阴雨天等不同天气,对高温季节河蟹生态养殖池塘水草稀疏区和水草密集区的水体溶解氧进行昼夜测定,并对强风天,池塘上下风处溶解氧进行测定。测定结果显示,池塘水体溶解氧14:00～16:00最高,4:00～6:00最低。高温季节无风晴天10:00～16:00河蟹池塘上下水层存在热阻力现象,导致上下层溶解氧存在显著差异(P<0.05),14:00最大差值为10.4 mg/L;6:00底层溶解氧为0.2～2.5 mg/L。强风天,在风力作用下,14:00上下层溶解氧差异缩小;6:00底层溶解氧为1.2～4.9 mg/L。阴雨天,光照强度较弱,上下层溶解氧差异最小,14:00最大差值为3.4 mg/L;6:00底层溶解氧为0.6～1.0 mg/L。晴天、多云等天气,水草密集区水体溶解氧显著高于水草稀疏区(P<0.05),而阴雨天夜晚水草稀疏区溶解氧略高于水草密集区。强风天,16:00下风处溶解氧显著高于上风处(P<0.05);6:00下风处溶解氧略高于上风处,但无显著差异(P>0.05)。此结果表明河蟹生态养殖池塘内水草是主要的溶解氧生产者,也为池塘增氧设备的使用提供一定的参考。

The dissolved oxygen was detected in crab eco-culture ponds within 24 hours in the high temperature season between the aquatic plant sparse area and the aquatic plant concentration areas,when it is sunny,windy and rainy.At the same time,the dissolved oxygen was detected between the upwind areas and the downwind areas on the windy day.The results show that the dissolved oxygen is the highest from 14：00 to 16：00,and the lowest from 4：00 to 6：00 within 24 hours.When it is 10：00-16：00 in the high temperature season,the thermal resistance appears between the upper and the lower water in the ponds,so the significant difference shows between the upper and the lower water（P0.05）.The maximum difference is 10.4 mg/L at 14：00.The dissolved oxygen is 0.2-2.5 mg/L in the lower water at 6：00.When it is strong winds,the difference is litter between the upper and the lower water at 14：00,and the dissolved oxygen is 1.2-4.9 mg/L in the lower water at 6：00.When it is rainy,the difference is least between the upper and the lower water,and it is 3.4 mg/L at 14：00.The dissolved oxygen is 0.6-1.0 mg/L in the lower water at 6：00.The dissolved oxygen in the aquatic plant concentration areas is significantly higher than the aquatic sparse area（P0.05）,except it is rainy.When it is windy,the dissolved oxygen in the downwind areas is significantly higher than the upwind areas at 16：00（P0.05）,but the no significant difference is showed at 6：00（P0.05）.In conclusion,the aquatic plant is the main producers of the dissolved oxygen in the crab eco-culture ponds.The research provides some reference for increasing dissolved oxygen in the crab eco-culture ponds.