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根据2014年4~9月在辽河口芦苇湿地不同河蟹养殖区进行的环境调查数据,分析了各养殖区氮、磷营养盐和COD等指标的变化。结果表明,氨氮浓度变化范围为0.04~1.25mg/L,在7月底达到最高,9月最低。各养殖区水体亚硝酸氮浓度变化范围为0.0017~0.0147mg/L;养殖区1、2、3、4亚硝酸氮浓度分别在9、4、6和7月底最高,均在8月浓度最低。各养殖区水体硝酸氮浓度变化范围为0.0015~0.0636mg/L;养殖区1和2整体表现为先减后增趋势,而养殖区3和4则大致呈先增后减的趋势。各养殖区水体磷酸盐浓度随时间变化趋势基本一致,大致呈先增后减趋势,整体变化范围为0.0024~0.0660mg/L。总氮浓度变化范围为0.65~6.88mg/L,变幅较大,在6月或7月最高,4月值最低。总磷浓度变化范围为0.05~0.31mg/L,7月中旬值最大,7月底值最小。COD变化范围为1.54~4.68mg/L,7月中旬值最大,6月值较小。总体上,各水质指标浓度均大致呈现6~8月较高,4月和9月较低的变化趋势。不同养殖模式下水质状况不同,建议苇田河蟹养殖过程中适度减少投饵量、合理控制养殖密度和适当增加投喂间隔,从而降低河蟹养殖对湿地水体污染风险。
According to the environmental survey data from different crab culture areas of reed wetland in Liaohe Estuary from April to September in 2014, the changes of nitrogen and phosphorus nutrients and COD were analyzed. The results showed that the ammonia concentration ranged from 0.04 to 1.25 mg / L, reaching the highest at the end of July and the lowest in September. The concentrations of nitrite nitrogen varied from 0.0017 to 0.0147 mg / L in all aquaculture areas. The concentrations of nitrite and nitrite in aquaculture areas were the highest at 9, 4, 6 and 7, respectively, with the lowest concentration in August. The concentrations of nitrate nitrogen varied from 0.0015 to 0.0636 mg / L in all culture areas. The overall performance of culture areas 1 and 2 decreased first and then increased, while that of culture areas 3 and 4 increased first and then decreased. The trend of phosphate concentration in aquaculture water was basically the same with time, roughly increasing first and then decreasing trend, the overall range of variation was 0.0024 ~ 0.0660mg / L. The total nitrogen concentration ranged from 0.65 to 6.88 mg / L, with larger amplitude, highest in June or July and lowest in April. Total phosphorus concentration ranged from 0.05 to 0.31 mg / L with the highest value in mid-July and the lowest value at the end of July. COD range of 1.54 ~ 4.68mg / L, mid-July maximum, June value smaller. Overall, the concentrations of water quality indicators are generally higher from June to August, April and September, the trend of the lower. Different aquaculture modes have different water quality, and it is suggested to reduce the feeding amount properly in reed crab farming, control the breeding density rationally and increase the feeding interval appropriately, so as to reduce the pollution risk of crab farming to wetland water body.