Water and sediment quality parameters of the restored mangrove ecosystem of Gurupura River and natural mangrove ecosystem of Shambhavi River in Dakshina Kannada, India

Restoration of Rhizophora mucronata stand in the Gurupura Estuary resulted in improved water and sediment quality parameters. Monthly monitoring from 2011 to 2016 indicates that the restored mangroves grew to a height of 61.49 +/- 5.76 cm. Principal component analysis (PCA) showed that increased duration of salinity in the estuary aided the growth of barnacles in planted mangroves which reduced survival by 10%. The United States Environmental Protection Agency ratings revealed that natural mangrove site in Shambavi River exhibit the maximum good water quality rating though dissolved inorganic phosphorous was rated highest due to non-point pollution sources. The pH, salinity, dissolved oxygen, silicate, phosphate, ammonia, and rainfall demonstrated significant seasonal differences (P < 0.001). Mangrove roots and biomes aided in accumulation of clay and significant difference (P < 0.001) was observed yearly. Land use management, efficient waste disposal system along with restoration of diverse mangroves can improve the water quality of estuarine ecosystem.

Automated summary

Restoration of Rhizophora mucronata stand in the Gurupura Estuary improved water and sediment quality. Increased salinity duration promoted barnacle growth in planted mangroves, but decreased survival rate. The natural mangrove site in Shambavi River had the highest water quality rating, with dissolved inorganic phosphorous being the highest due to non-point pollution sources. These findings suggest that land use management and mangrove restoration can enhance estuarine water quality.