Abstract
This study evaluates the biodiversity of mangrove flora and associated macrofauna alongside physicochemical parameters of estuarine water and sediment, across four distinct sites in Goa (Verem, Nerul, Britona, and Divar). The objectives were to assess spatial variations in water and sediment quality, characterise the diversity of mangroveassociated communities using biodiversity indices, vegetation analysis, and correlate environmental parameters with biological diversity to elucidate the impact of anthropogenic pressure on mangrove ecosystems. Standardized sampling and laboratory protocols were employed for species identification and physicochemical analyses, including pH, temperature, salinity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), nitrates, and phosphates. Results revealed approximately 11 mangrove species across study sites. Physicochemical parameters exhibited site-specific variation: pH ranged from 6.75 to 7.52, salinity from 22 to 35 ppt, and temperature from 26 °C to 31°C. DO concentrations (5.22–7.97 mg/L) and BOD values (1.64–4.2 mg/L) indicated varying organic matter content, while COD values (0.16–0.84 mg/L) suggested differing degrees of pollution. Nutrient analysis showed phosphate concentrations between 0.01 and 0.25 mg/L in water and 0.11 to 0.34 mg/L in sediments, with nitrates ranging from 1.39 to 4.62 ppm in water and 0.24 to 12.36 ppm in sediments. Higher biodiversity indices, including Shannon-Wiener and Margalef, were associated with sites exhibiting lower organic and chemical pollution, signifying healthier ecological conditions. Conversely, sites with elevated nutrient and organic pollutant levels corresponded with diminished biodiversity, reflecting anthropogenic impacts. The study underscores the critical link between estuarine water quality and mangrove biodiversity, and highlights the urgency to implement conservation strategies to mitigate human-induced pressures on these vulnerable ecosystems in Goa.
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