Where the land meets the sea: Defining blue carbon extent within Nuu-chah-nulth Tribal Council boundaries

Abstract

Coastal wetlands such as tidal marshes, eelgrass, and estuaries have the unique ability to sequester carbon and are commonly known as blue carbon sinks. As the impacts of climate change worldwide are becoming intensified, the use of blue carbon sinks as a carbon management tool through carbon credits is an innovative way to manage carbon emissions. The study uses multidimensional Landsat imagery in a Principal Component Analysis to classify and identify coastal wetland areas using Random Forest and Support Vector Machine classifiers. The classified coastal wetlands are then used as an input in the Coastal Blue Carbon Integrated Valuation of Environmental Services and Trade-offs (InVEST) tool to evaluate carbon storage found within Nuu-Chah-Nulth Tribal Council (NTC) boundaries. Coastal wetland extents were found to have grown at rates of 58.93 % to 42.3 % over a twenty-year period. The total gross carbon emission for the entire study area was found to be between 3,188 to 21,415 tonnes of carbon. This study estimates that the total net gain in carbon storage for the entire study area ranges from 16,761 to 460,998.1 tonnes of carbon for the nominal year 2019. The study also estimated a future prediction of total net carbon storage where 80,750.97 to 852,387.04 tonnes of carbon are predicted to be stored within the study area by 2030. The estimated carbon storage and coastal wetland trends support the importance of land management and long-term planning within the study area. Interested groups such as NTC Nations can use this study as a foundation for future blue carbon projects, enabling them to define revenue streams using carbon tax incentives, eco-tourism, and prioritize restoration projects.