Selvam S, Muthukumar P, Roy Priyadarsi D, Venkatramanan S, Chung S Y, Elzain Hussam Eldin, Muthusamy S, Jesuraja K
Department of Geology, V.O. Chidambaram College, Thoothukudi, 628008, Tamilnadu, India.
Department of Geology, V.O. Chidambaram College, Thoothukudi, 628008, Tamilnadu, India; Registration No: 19212232221045, Affiliated to Manonmaniam Sundaranar University, Tirunelveli, 627 012, Tamil Nadu, India.
Chemosphere. 2022 Oct;305:135271. doi: 10.1016/j.chemosphere.2022.135271. Epub 2022 Jun 12.
The influx of fresh groundwater and re-circulated sea water into coastal ecosystem occurs through the submarine groundwater discharge (SGD). Measurement of salinity, radium tracers (Ra, and Ra isotopes) and nutrients in estuarine water, coastal surface water and groundwater during December 2019 estimated the SGD and associated nutrient fluxes near the Karameniyar estuary (Gulf of Mannar) and surroundings of the Manapad region at southern part of Tamil Nadu state in India. The presence of excessive radium tracers revealed that the SGD was contributing to Ra desorption from the sediments and enrichment in the coastal waters. We estimated SGD of approximately 0.03-0.59 m m d for the Manapad region and relatively more homogeneous but comparatively less values in the Karameniyar estuary (0.03-0.34 m m d). Higher average values of dissolved inorganic nitrogen (DIN; 43.62 μmol L) and soluble reactive phosphate (SRP; 1.848 μmol L) suggested greater influence of SGD on the overall coastal water nutrient budget. This study also indicated simultaneous occurrence of fresh and saline SGD in this region.
新鲜地下水和再循环海水通过海底地下水排放（SGD）流入沿海生态系统。2019年12月期间，对河口、沿海地表水和地下水中的盐度、镭示踪剂（镭和镭同位素）以及营养物质进行测量，估算了印度泰米尔纳德邦南部马纳帕德地区卡拉梅尼亚尔河口（马纳尔湾）及其周边地区的SGD和相关营养物质通量。过量镭示踪剂的存在表明，SGD导致沉积物中的镭解吸并在沿海水域富集。我们估算出马纳帕德地区的SGD约为0.03-0.59 m m d，而卡拉梅尼亚尔河口的SGD相对更均匀但数值相对较低（0.03-0.34 m m d）。溶解无机氮（DIN；43.62 μmol L）和可溶性活性磷（SRP；1.848 μmol L）的较高平均值表明SGD对整个沿海水体营养预算有更大影响。这项研究还表明该地区同时存在淡水和咸水SGD。
