Detailed geochemical studies of both major and minor elements in Bangladesh surface waters are sparse, particularly in shrimp aquaculture pond environments. Therefore, water samples from shrimp aquaculture ponds and tidal channels were collected in high precipitation (July) and low precipitation (May) months from 2018–2019 in Southwest Bangladesh and analyzed for complete water chemistry. Selenium (Se) and arsenic (As) were elevated above WHO guidelines in 50% and ~ 87% of samples, respectively, but do not show any recognizable spatial patterns. Shrimp pond and tidal channel water compositions in the dry season (May) are similar, illustrating their connectivity and minimal endogenous effects within shrimp ponds. Tidal channels are less saline in July than shrimp ponds still irrigated by tidal channels, suggesting that either farmers limit irrigation to continue farming saltwater shrimp, or the irrigation flux is low and leads to a lag in aquaculture-tidal channel compositional homogenization. δ18O and δ2H isotopic compositions from samples in May of 2019 reveal tidal channel samples are closer to the local meteoric water line (LMWL) than shrimp pond samples, because of less evaporation. However, evaporation in May shrimp ponds has a minimal effect on water composition, likely because of regular drainage/exchange of pond waters. Dissolved organic carbon (DOC) is positively correlated with both δ18O and δ2H in shrimp ponds, suggesting that as evaporation increases, DOC becomes enriched. Multiple linear regression reveals that As and Se can be moderately predicted (adjusted R2 values between 0.4 and 0.7, p < 0.01) in surface waters of our study with only 3–4 independent predictor variables (e.g., Ni, V and DOC for Se prediction; Cu, V, Ni and P for As prediction). Thus, this general approach should be followed in other regions throughout the world when measurements for certain hazardous trace elements such as Se and As may be lacking in several samples from a dataset.

中文翻译：

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孟加拉国西南部潮汐通道和养殖虾池水化学成分的影响

对孟加拉国地表水中主要和次要元素的详细地球化学研究很少，特别是在对虾养殖池塘环境中。因此，在孟加拉国西南部 2018-2019 年的高降水（7 月）和低降水（5 月）月份收集了对虾养殖池塘和潮汐通道的水样，并分析了完整的水化学。硒 (Se) 和砷 (As) 分别在 50% 和 ~ 87% 的样本中高于 WHO 指南，但没有显示任何可识别的空间模式。旱季（5 月）的虾塘和潮汐渠水成分相似，说明它们的连通性和虾塘内的内源性影响最小。七月的潮汐通道比仍然由潮汐通道灌溉的虾池的盐分少，表明要么农民限制灌溉以继续养殖咸水虾，要么灌溉通量低并导致水产养殖 - 潮汐通道成分均质化滞后。2019 年 5 月样本的 δ18O 和 δ2H 同位素组成表明，由于蒸发较少，潮汐通道样本比虾塘样本更接近当地大气水线 (LMWL)。然而，5 月虾塘的蒸发对水组成的影响很小，可能是因为池塘水的定期排水/交换。溶解有机碳 (DOC) 与虾塘中的 δ18O 和 δ2H 均呈正相关，表明随着蒸发量的增加，DOC 变得更加丰富。多元线性回归表明 As 和 Se 可以适度预测（调整后的 R2 值在 0.4 和 0.7 之间，p < 0。01）在我们研究的地表水中，只有3–4个独立的预测变量（例如，Ni，V和DOC用于Se预测； Cu，V，Ni和P用于As预测）。因此，当数据集中的多个样本中可能缺少某些有害痕量元素（如 Se 和 As）的测量值时，世界其他地区应遵循这种通用方法。