Octavia Barra1, Milen Duarte2, Fadia Tala2, Julio Vasquez3, Macarena Bravo3, Alejandra V. González1
1Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, 2Instituto de Ecología y Biodiversidad, Facultad de Ciencias, Universidad Austral de Chile. Campus Isla Teja. Valdivia, 3Departamento de Biología Marina, Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Instituto Milenio en Socioecología Costera (SECOS), Facultad de Ciencias del Mar, Universidad Católica del Norte, 4Instituto de Políticas Públicas, Universidad Católica del Norte, Coquimbo, Chile
Kelps are responsible for the carbon dioxide sequestration of coastal marine ecosystems, which is key to climate change adaptation and mitigation. It is also a key factor in developing the blue carbon economy and climate action. To harness the potential of kelps, the Chilean government plans to implement sustainable development strategies. A first key step is to determine the carbon sequestration capacity of the Chilean kelp species. In this work, we studied two allopatric species Lessonia berteroana and L. spicata, that inhabit the same ecological niche and are also sold as raw materials. We analyzed samples of holdfast and frond tissue from four different localities to estimate the percentage of carbon present. Next, we did a literature review to create a model that represents the dynamics of the carbon capture system in each species. From this review, we identified the existing components, interactions, and missing information. Our results indicate that L. berteroana has a higher carbon composition than L. spicata. The carbon composition varies depending on the season and tissue type. We found that fronds captured 1-8 times more CO2 than the holdfast. This result suggests that the most used estimates of carbon capture and sequestration may probably overestimate the actual percentages of capture in natural settings. Future blue carbon studies should thus consider these differences to make better projections of carbon stored in tissues, and to generate predictive models that allow for the strategic analysis of nature-based climate action and the potential blue economy.
Funding: FONDEF ID 20I10167, Packard 2021-73304