Physicochemical Characteristics of Surface Waters in the Habitats of Enhalus acoroides and Halodule uninervis in Palk Bay, Tamil Nadu, India

Background: Hydrological studies are essential for understanding the interactions among various trophic levels and the structure of food webs. In recent years, significant attention has been devoted to analyzing the physicochemical parameters of coastal waters to assess water quality and the biodiversity of seagrass meadows. Aim: This study aimed to investigate the seasonal changes of physicochemical parameters of selected seagrass meadows in the Kattumavadi, Palk Bay, India. Methods: Field collections were carried out over a two-year period, from June 2011 to June 2013, at monthly intervals to record various physicochemical parameters in two selected seagrass meadows (Enhalus acoroides and Halodule uninervis). The observations were categorized into four seasons: post-monsoon (January–March), summer (April–June), pre-monsoon (July–September), and monsoon (October–December), using standard methods. Results: The seasonal analysis revealed elevated concentrations of nitrate, nitrite, phosphate, and particulate organic carbon (POC) in the seagrass meadows. Results revealed that there is no difference in the physico-chemical variables between the micro-habitats of the two species and there are clear differences in the physico-chemical variables between the seasons. The water quality of Palk Bay at Kattumavadi remains within normal limits, with no evidence of coastal pollution despite the recent development of aquaculture in the region. Conclusion: Continuous, long-term monitoring and assessment are crucial to safeguard the health, safety, and sustainability of the region’s flora and fauna, thereby ensuring the preservation of ecosystem biodiversity.