Saltmarsh Conservation & Rehabilitation

Methodology overview

Methodology for carbon credit generation through saltmarsh ecosystem protection and restoration, covering tidal wetland carbon dynamics and long-term sediment accumulation.

Eligibility criteria

• ●Tropical or temperate mangrove, saltmarsh or seagrass habitat with ecological feasibility evidence (hydrology, salinity, sediment supply, donor stock).
• ●Documented land or seabed tenure for the full crediting period, with written community consent where customary rights exist.
• ●Historical baseline of at least 10 years of land-cover and degradation data (Sentinel-2 / Landsat back-cast).
• ●Additionality demonstrated through barrier analysis: aquaculture pressure, encroachment, sediment starvation or active dieback.
• ●Permanence plan implementing buffer pool drawdown (Option C) plus methodology-specific reversal monitoring.
• ●MRV plan covering soil/sediment carbon, above- and below-ground biomass, and lateral export with site-specific defaults.
• ●Contribution-first claims only — no neutralisation language, no fungibility with non-marine pools.

Quantification approach

Carbon pools and crediting metrics

• ●Above-ground biomass (AGB) — allometric or LiDAR-derived
• ●Below-ground biomass (BGB) — root-to-shoot ratios calibrated regionally
• ●Soil / sediment organic carbon (SOC) — top 1 m unless deeper cores are justified
• ●Dead wood and litter (de minimis; reported but not credited unless > 5% of stock)
• ●Lateral DIC / POC export (subtracted from gross removal where measurable)

Equations (in plain language)

• 1.Net removals = (stock change in AGB + BGB + SOC) minus (project emissions + leakage + lateral export).
• 2.Stock change uses paired plots or chronosequence with project / control design — not single-year snapshots.
• 3.SOC change is gain-loss where direct cores exist, or stock-difference where modelled with site-calibrated sequestration rates.
• 4.Lateral export defaults are conservative until two consecutive verifications produce site-specific data.

Reference methodology — starting point

IPCC 2013 Wetland Supplement (Chapter 4, Coastal Wetlands) is the starting reference. Tier 2 default factors are used as a floor; Tier 3 calibration is required before any uplift above default sequestration rates can be credited.

Where MCC improves on the reference

• ✓Mandatory ex-ante drawdown of buffer pool credits before issuance — not a paper reserve.
• ✓AI-assisted change detection on Sentinel-2 NDVI and Sentinel-1 SAR, with anomaly review by human verifiers within 14 days.
• ✓Lateral export accounted for explicitly rather than assumed-zero.
• ✓Contribution-first crediting unit: removals are reported in tCO2e but never marketed as offsets.

Monitoring requirements

Required data sources

• ●Sentinel-2 NDVI / NDWI — quarterly, 10 m resolution
• ●Sentinel-1 SAR backscatter — annual, for canopy and inundation under cloud
• ●Sediment carbon density samples — LECO CN628 dry combustion every 3 years
• ●Permanent plot AGB / BGB measurements — every 5 years, 30 plots minimum per 1,000 ha
• ●GPS-tagged photo points — biannual, minimum 1 per 50 ha
• ●Tide-gauge / sediment-elevation tables (SET) where elevation accretion is claimed

KPIs that must be tracked

Eligible co-benefits — SDG mapping

F-family F01 contributes to the following Sustainable Development Goals. Indicators flagged as required must be reported at every verification; optional indicators may be claimed where the project chooses to report them.

Public consultation and community engagement

30-day public consultation is mandatory at PDD stage. For projects that overlap customary or indigenous tenure, FPIC documentation must accompany the PDD and be re-confirmed at every verification. Local-language summaries (minimum 1,500 words) are required.

Adopted documents and version history

The binding text for this family is the adopted guidance published at /transparency/documents, together with the register entry above. Version history is carried by those documents, not by this page.