What Is Blue Carbon
Blue carbon refers to the carbon stored and sequestered by coastal and marine ecosystems — primarily mangrove forests, seagrass meadows, and salt marshes. These ecosystems store carbon at rates far exceeding terrestrial forests, both in their vegetation and in the water-saturated soils beneath them where organic matter can accumulate undisturbed for millennia. When these ecosystems are degraded or destroyed, their stored carbon is released, contributing significantly to atmospheric greenhouse gas concentrations.
The Scale of the Opportunity
Coastal blue carbon ecosystems cover only 0.2% of the ocean surface but may account for more than 50% of carbon burial in marine sediments. Protecting existing blue carbon ecosystems from conversion — the dominant loss pathway through coastal development, aquaculture expansion, and pollution — is among the most cost-effective climate mitigation actions available. Restoring degraded mangroves, seagrasses, and salt marshes expands this sequestration capacity while delivering substantial co-benefits for coastal protection and fisheries.
Measurement and Monitoring
Credible blue carbon accounting requires robust measurement of ecosystem extent, carbon stock density, and sequestration rates. Satellite-based mapping provides ecosystem extent at global scale. Field measurements of soil carbon density and accumulation rates provide the ground truth for converting area data to carbon stock estimates. OrcaGuard's monitoring program integrates these approaches with continuous sensor data to provide higher temporal resolution carbon flux measurements than traditional sampling approaches allow.
Blue Carbon Finance
Carbon markets provide a mechanism for directing investment toward blue carbon conservation and restoration. Voluntary carbon market projects generating verified emission reductions from coastal ecosystem protection are attracting increasing interest from corporate buyers seeking high-quality nature-based carbon credits. The combination of carbon value with biodiversity co-benefits and coastal protection services makes well-designed blue carbon projects compelling investments.