Groundwater contributed nutrients aided with increasing population threaten the global coastal ecosystems. In this study, attempt has been made using major ions and nutrients to evaluate the significance of submarine groundwater discharge (SGD) in a semi-arid estuary of south India. Surface, seepage and groundwater chemistry altered from fresh (NaK-CaMg-NO₃Cl) to mixed (NaK-NO₃Cl) to saline water (NaCl) type from upstream to outlet that connects Bay of Bengal. We predicted abundant nitrate (NO₃⁻) along upstream and towards the bay due to application of fertilizers and aquaculture activities, respectively. Elevated ammonium (NH₄⁺) observed in the recirculated groundwater/sea water suggests contribution from sea water intrusion and higher phosphate (PO₄³⁻) noted at the outer bay suggests sources from phosphatic nodules. Decreasing Redfield ratio towards the bay suggests anoxic aquifer condition due to salinization. The SGD driven nutrient fluxes were 40.0–47.0% for NO₃⁻, 43.0–51.0% for NH₄⁺ and 9.0–32.0% for PO₄³⁻ from the total input fluxes. The estimated nutrient fluxes showed that NO₃⁻ and PO₄³⁻ discharges to the sea due to SGD and NH₄⁺ removed from the coast due to consumption by microorganisms that creates toxic algal blooms in the study area.

地下水贡献的养分随着人口的增加而受到威胁，威胁着全球沿海生态系统。在这项研究中，已经尝试使用主要离子和养分来评估印度南部半干旱河口海底地下水排放（SGD）的重要性。从上游到连接孟加拉湾的出口，地表，渗流和地下水化学从新鲜的（NaK-CaMg-NO ₃ Cl）变为混合的（NaK-NO ₃ Cl）到盐水（Na Cl）类型。我们预测硝酸盐丰富（NO ₃ ^-分别沿上游和朝向托架由于肥料和水产养殖活动的应用）。高铵（NH ₄ ⁺）在再循环的地下水/海水中观察到，表明来自海水入侵，而在外海湾发现的较高的磷酸盐（PO ₄ ^3-）则表明来自磷结核。朝向海湾的Redfield比率降低表明由于盐碱化导致缺氧含水层状况。在SGD驱动养分通量分别为40.0-47.0％为NO ₃ ^-，43.0-51.0％为NH ₄ ⁺和9.0-32.0％为PO ₄ ^3-从总输入通量。所估计的营养盐通量表明，NO ₃ ^-和PO ₄ ^3-排放到海因SGD和NH ₄ ⁺ 由于被微生物消耗而从海岸带走，微生物在研究区域内产生有毒的藻华。