National Centre for Sustainable Coastal Management
Ministry of Environment, Forest and Climate Change
Government of India

FTR Research

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Climate Change

Blue Carbon Stock Assessment

Estimatation of carbon stock in seagrass, mangroves and salt marshes is essential as they are the ecosystems with high carbon seqhetration rates can capture two-thirds of the organic C in marine environment.

During the UN Conference of Parties on Climate Change, Paris,-2015, India submitted Intended Nationally Determined Contribution (INDC) outlining the intended post-2020 climate actions. The target fixed by the Govt. of India to reduce net GHG emission intensity, includes the creation of an additional (cumulative) carbon sink of 2.5–3 GtCO2e through additional forest and tree cover by 2030.

Coastal vegetated ecosystems namely marshes, mangroves, and seagrass, termed "blue carbon", are well known for their effective high rates of annual carbon sequestration and the storage of the sequestered C on longer time scales. Coastal ecosystems are well known for the efficient C sequestration and storage capacity and could effectively mitigate the increase in atmospheric GHG concentration. Blue carbon ecosystems provide an essential support system for climate change adaptation along the coastline globally by sequestering significant amounts of carbon from the atmosphere and ocean.

Carbon pools in blue carbon vegetation and the top meter of sediment are most susceptible to land-use change and are often termed here ‘near-surface’ carbon. Lack of a comprehensive database on blue carbon sequestration and GHG emission from the ecologically important coastal ecosystems in India is a well-established fact. It is essential to create a carbon inventory for a coastal ecosystem to provide

Past and present distribution of coastal vegetated ecosystems linked to the human uses of the area
Current carbon stock within the project area and rate of carbon accrual
Potential carbon emissions that will result from expected or potential changes to the landscape.

Approach

Carbon Stock Assessment

(a) Following carbon stocks in a blue carbon ecosystem are being estimated as reservoirs that store and release carbon

  • The living above ground biomass: Primarily herbaceous (for seagrass and tidal salt marsh) and woody (for mangroves) plant mass
  • The living below ground biomass dominated by roots and rhizomes
  • The dead aboveground biomass, primarily leaf detritus (in all three ecosystems) or wood (in mangroves), and other organic debris such as macro-algae.
  • The belowground carbon comprised of dead plant tissues and soil organic matter (‘autochthonous’ and ‘allochthonous’ carbon).
  • Dissolved Carbon (organic and inorganic) associated with surrounding water.

(b) Source Apportionment of Organic Carbon ( Source-Sink characterstics)

  • Measuring residence time and turnover rates of sequestered C in each compartment of individual ecosystem
  • Fractionation of labile (degradable) and non-labile (non-degradable/ refractory) sedimentary organic matter
  • Determination of the biogeochemical characteristics of interstitial water in mangrove sediments/ root systems including processes such as anamox/ sulphate reduction/ methanogenesis/ Nitrification and denitrification rates
  • Source characterization of Sediment Organic Matter (OM) using stable isotopes and biomarker studies