Eco-engineering of coastal environment through saltmarsh restoration towards climate change impact mitigation and community adaptation in Bangladesh

Abstract

A field research was undertaken to investigate the effects of saltmarsh restoration and some eco-engineering activities on the climate change impact mitigation and community adaptation in the coastal environment of Sonadia Island, Cox’s Bazar, Bangladesh. Two research sites viz., saltmarsh restoration site (SMRS) and impacted site (IP) were selected for this study. Amount of carbon assimilation by saltmarsh plant Porteresia coarctata at SMRS was increased from 165.17 ± 68.35 to 198.18 ± 41.32 g/m2 during the study. The highest carbon assimilation (198.18 ± 41.32 g/m2) was noticed during winter, while the highest biomass (10.47 ± 0.25 kg/m2) was measured from SMRS. Soil compactness, organic matter, organic carbon, field water capacity, plant height, plant biomass and shoot density were found to be significantly (p < 0.05 to 0.01) higher in the SMRS than that of the IS. Seasonal variations of air temperature, water temperature, water pH, water salinity, water transparency, tidal height, inundation period, wave velocity, soil temperature, soil pH, pore water salinity, sedimentation, soil texture particle density, plant height, biomass and shoot density at different significance levels (p < 0.05 to p < 0.01) were noticed throughout the study. Correlation matrix showed that the plant height, biomass and shoot density were positively correlated with sedimentation, and negatively correlated with wave velocity at different significant levels (p < 0.05 to p < 0.01). From the present study, it is evident that SMRS, which was controlled and managed with some artificial inputs not only showed the elevated levels of plant height, biomass, shoot density, sedimentation and carbon assimilation but also exhibited remarkable changes in some of the factors studied rather than impacted site (IS), the findings of which could be helpful for the protection of coastal environment as well as mitigation of climate change impact that will ultimately save the local community from natural calamities in the long run.