Wetlands and climate change: preserving carbon sinks in the Pacific region

With their incredible ability to capture and store carbon, wetlands can be a solution to the climate crisis. As they are considered Nature-based Solutions, the Pacific Community (SPC) recognises the efforts to preserve wetlands to address climate change issues. Aligned with the 2022 World Wetlands Day's theme, "Wetland's action for people and nature", SPC takes action to preserve these natural resources.

The picture is alarming: scientists estimate that 64% of the planet's wetlands have disappeared since 1900. As higher temperatures worsen and increase the frequency of storms, floods, heatwaves, and droughts due to climate change – and so is the direct impact on ecosystem services like wetlands and local populations in Pacific Islands Countries and Territories (PICTs).

In the Pacific region, the most common wetlands are mangroves and coral reefs, accounting for 3% and 25% of the global surface on the planet. The current state of Pacific wetlands is continually impacted by threatened by invasive alien species, pollution, over-harvesting and climate change. The degraded habitats give rise to a loss of carbon stored in soil, changes in soil structure and saltwater intrusion to freshwater coastal wetlands.

"The consequences of global warming could change wetlands forever, but wetlands can also play a crucial role in combating climate change, supporting adaptation and resilience to these effects. In good condition, vegetated wetlands are among the most effective carbon sinks. If we add aquaculture that is ‘climate-smart’ and ‘nature positive’, then mangrove wetlands can become even more effective as carbon sinks.” says Dr Tim Pickering, Pacific Community Inland Aquaculture Advisor.

In Fiji, the Pacific Community is implementing a' climate smart' aquaculture project that supports communities to move from collecting wild oysters to farming them, to provide an additional source of food security and a sustainable alternative livelihood. Since implementing this project, oysters have reached marketable size and now contribute to catering for community events, plus they have found acceptance in Suva restaurants.

This project helps to advance climate adaptation as farmed oysters sequester carbon in their shells and deposit pseudo-faeces into seabed sediments, permanently locking this carbon into the area's geology. It is also an example of ‘nature positive’ aquaculture that improves the environment. Oysters are filter-feeders that remove nutrients from the water: they can help mitigate the eutrophication of coastal waters. The farm structures (baskets tied to stakes) are artificial reefs that provide additional habitat, increasing the abundance of finfish and edible seaweeds in the area.

“As marine and terrestrial ecosystems are directly linked, PICTs are encouraged to incorporate land-sea processes to address climate change issues and sustainable development. Protecting wetlands includes adopting integrated management approaches implementing forest management actions to maintain control over downstream sediment export and related discharge from land thereby impacting the marine ecosystem goods and services on which human wellbeing depends.” explains Samasoni Sauni, Pacific Community Ridge to Reef Programme Coordinator.

SPC is committed to enhancing integrated approaches to freshwater and coastal area management. It has deployed the Regional International Waters Ridge to Reef Project  which included a Spatial Prioritization Model (SPM) to support national land-sea decision making on natural resources. This innovation enables decision-makers to trial policy actions by exploring management scenarios and identifying priority areas for conservation and protection to guide future investments.

Trialled in partnership with the Government of Vanuatu, the SPM uses the InVEST sediment model, a plume model, and a predictive coral reef model for land cover, land management, urbanization, and marine management scenarios. The model outputs provide the science and evidence supporting policy decisions to identify and select priority sites and areas for protection.

An encouraging mixed-management case scenario of terrestrial and marine protected area actions included restoration of up to 1,330 hectares of native forest , 75 hectares of marine habitat and 8.3 tonnes of fish biomass, together with a decrease in sediments by 210 tonnes per year.

“The R2R concept provides a framework that not only ensures maintenance of ecosystem services including wetlands preservation, but also provides for the holistic cross-sectoral management and governance of water, pollution control, sustainable land use, agriculture and forestry practices, balancing sustainable use and conservation, climate variability and change.” highlights Samasoni Sauni.

Recognizing the vital role of coastal and marine ecosystems in supporting livelihoods and sequestering carbon across the globe, SPC is committed to supporting efforts to conserve and manage wetlands recognising their ecological functions on ecosystem integrity, and their economic value and contribution to subsistence.

Know more about SPC’s work to preserve wetlands and natural resources:


Climate Change and Environmental Sustainability (CCES) Programme

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