Variation in sediment organic carbon stock in Bhitarkanika wetlands, India

Abstract

Wetlands are known to sequester atmospheric CO₂ in biomass and sediments, often referred to as “blue carbon” of the ocean. The present research has tried to focus on depth-wise (0-10, 10-20, 20-30, 30-40 and 40-50 cm) profile of sediment organic carbon (OC) along with temperature, pH, electrical conductivity (EC) and bulk density (BD) seasonally in Bhitarkanika wetlands at five different locations for two years 2016-17 and 2017-18, respectively. Variation of sediment temperature with depth ranged from 21.32±0.76 to 34.13±0.58 °C, pH ranged from 4.8±0.28 to 6.6±0.75, EC ranged from 0.167±0.08 to 1.814±1.89 Sm^-1, BD ranged from 740±0.06 to 125±0.17 kg m^-3 and OC ranged from 0.24±0.14 to 3.57±0.80 %, respectively. Variation of OC between season, depth and stations has been proved through ANOVA analysis. The study revealed approximately 22.45±11.24 to 63.51± 37.84 t ha^-1CO₂equivalent is being absorbed by the sediment compartment in this mangrove ecosystem, confirming the potentiality of mangrove sediment as a sink of carbon dioxide.