Veenstra J, Nolen S, Carroll J, Ruiz C
Oklahoma State University, 107 Engineering South, Stillwater, OK 74078, USA.
Water Sci Technol. 2003;47(12):293-300.
A 3-year study was conducted by the U.S. Army Corps of Engineers assessing water quality related impacts of aquaculture of 250,000 channel catfish (Ictalurus punctatus) in floating net pens in the Rock Creek Arm of Lake Texoma, Oklahoma/Texas. Five large nylon nets suspended from a floating framework of galvanized metal anchored in open water 100 m offshore made up the net pens with fish stocking densities varying from 88 to 219 fish/m3. Water quality sampling was conducted biweekly from April to September and monthly from October to March at three locations. On all sampling dates field measurements of water temperature, pH, dissolved oxygen, and conductivity were recorded at 1 m depth intervals and water samples were collected at a depth of 0.6 m and near the bottom of the water column at each site. Sample analyses included: total alkalinity, total hardness, turbidity, chloride, sulfate, orthophosphate, total phosphorus, nitrate-N, nitrite-N, total Kjeldahl nitrogen, total organic carbon, dissolved organic carbon, biochemical oxygen demand, and chlorophyll a. The results showed statistically significant decreases in water temperature and dissolved oxygen and significant increases in field conductivity in surface waters near the net pens relative to other sampling sites. The most dramatic water quality effect observed during the study was decrease in dissolved oxygen levels near the net pens following lake turnover in the second year.
美国陆军工程兵团进行了一项为期3年的研究，评估在俄克拉荷马州/德克萨斯州特克索马湖岩溪湾的浮动网箱中养殖25万条斑点叉尾鮰（Ictalurus punctatus）对水质的相关影响。五个大型尼龙网悬挂在离岸100米开阔水域中由镀锌金属制成的浮动框架上，构成了网箱，鱼的放养密度从88至219尾/立方米不等。从4月至9月每两周进行一次水质采样，10月至3月每月在三个地点进行采样。在所有采样日期，均在1米深度间隔记录水温、pH值、溶解氧和电导率的现场测量数据，并在每个站点0.6米深度和水柱底部附近采集水样。样本分析包括：总碱度、总硬度、浊度、氯化物、硫酸盐、正磷酸盐、总磷、硝酸盐氮、亚硝酸盐氮、凯氏总氮、总有机碳、溶解有机碳、生化需氧量和叶绿素a。结果表明，与其他采样点相比，网箱附近表层水体的水温及溶解氧在统计学上显著降低，现场电导率显著升高。在研究期间观察到的最显著的水质影响是在第二年湖泊翻转后网箱附近溶解氧水平的下降。
