Institute for Marine Remote Sensing, College of Marine Science, University of South Florida, 140 7th Ave. South, St. Petersburg, FL, 33701, USA.
Aquaculture Department, National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt.
Environ Monit Assess. 2018 Jun 27;190(7):436. doi: 10.1007/s10661-018-6800-6.
Coastal aquaculture is faced with extreme variation in water quality. The Deeba Triangle on Lake Manzala is the largest marine coastal aquaculture-producing area on the Egyptian Mediterranean. Samples from 16 ponds were taken during four seasons (2014-2015), to investigate the variation of 12 water quality parameters at that region. We tested the hypothesis that there is no spatial or temporal variation in water quality of the fish ponds. Fish ponds were statistically clustered into three groups (p = 0.0005) coincident with their geographical location. Hypersaline and transparent waters characterized the western ponds; higher dissolved oxygen and higher nutrients characterized the central region. These spatial differences were principally due to variations in salinity and nutrients of the water sources used for irrigation of the ponds and to differences in the aeration management styles. Strong seasonality was seen in water temperature (following air temperature), nutrients, and turbidity (following the seasonal cycles of various water sources from the Lake Manzala and the seasonality of the petrochemical plants effluents close to these ponds). We conclude that municipal effluents significantly affected, spatially and temporally, the quality of the irrigation water used for coastal aquaculture purposes, which consequently might affect fish yield.
沿海水产养殖面临水质极端变化的挑战。曼扎拉湖的迪巴三角区是埃及地中海最大的海洋沿海水产养殖区。在四个季节（2014-2015 年）中，从 16 个池塘中采集样本，以研究该地区 12 个水质参数的变化。我们检验了池塘水质没有时空变化的假设。池塘按地理位置统计聚类为三组（p=0.0005）。西部池塘的水呈高盐度和高透明度特征；中部地区的溶解氧和养分较高。这些空间差异主要是由于灌溉池塘的水源盐度和养分的变化以及池塘曝气管理方式的不同造成的。水温（随气温变化）、养分和浊度（随来自曼扎拉湖的各种水源的季节性变化以及靠近这些池塘的石化厂废水的季节性变化）表现出很强的季节性。我们得出结论，城市废水显著影响了沿海水产养殖灌溉用水的水质，从而可能影响鱼类产量，这种影响具有时空差异。
