Changes in dynamics of nutrient with respect to partial pressure of dissolved CO₂ [pCO₂(water)] from tropical lotic ecosystem, namely diamond harbor an end member of Hugli estuary, were analyzed by way of a microcosm experiment. Though surface waters behaved as an extensive CO₂ source under in-situ condition [in-situ pCO₂(water) ranged from ~1000 to ~20,000 ppm], it was capable of becoming a sink in post-monsoon while pH as well as primary productivity was significantly high (monitored in microcosm). In pre-monsoon and monsoon, internal generation of nutrients by means of re-mineralization was pre-dominant and the CO₂ source character of the water was maintained for eight consecutive days (the duration of the microcosm). Amongst the five nutrients, dissolved nitrate-nitrogen (NO₃-N) followed by phosphate-phoshorus (PO₄-P) were the most utilized nutrients during higher photosynthetic activities and conditions conducive for optimum photosynthesis can lower the magnitude of CO₂ source character. Substantial nutrient utilization efficiency especially during post-monsoon enabled photosynthetic CO₂ utilization because of low turbidity and optimum light availability. It infers that controlled freshwater discharge from the Farakka Barrage along with proper replenishment with freshwater borne nutrients could minimize the re-mineralization process and lessen the CO₂ source potential of this estuary.

中文翻译：

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描绘二氧化碳和叶绿素-城市河口相对于可利用的溶解性养分变化的变异性：微观研究

通过微观实验分析了热带热带生态系统（即休利河口末端的钻石港）养分相对于溶解的CO ₂ [pCO ₂（水）]分压的动态变化。尽管在原位条件下地表水表现为广泛的CO ₂源[原位pCO ₂（水）范围从〜1000到〜20,000 ppm]，但它能够在季风后变成沉池，而pH值和初级生产力显着较高（从微观角度进行监控）。在季风前和季风中，通过再矿化作用内部养分的生成占主导地位，CO ₂水的来源特征连续八天（缩影的持续时间）得以维持。在这五种养分中，在较高的光合作用期间，溶解的硝态氮（NO ₃ -N）其次是磷酸盐-磷（PO ₄ -P）是利用最多的养分，并且有利于最佳光合作用的条件可以降低CO ₂来源特征的幅度。。大量的养分利用效率，特别是在季风后的光合作用CO _2期间由于浊度低和最佳的光利用率，因此利用率高。据推断，控制法拉卡卡堰坝的淡水排放，并适当补充淡水传播的养分，可以最大程度地减少再矿化过程，并降低该河口的CO ₂排放源潜力。