Impacts of El Nino events on ecosystem services provided by Colombian mangroves

The current El Niño event in the tropical Pacific region is forecast to be one of the two strongest since records began. There is increasing evidence of links between the El Niño-Southern Oscillation (ENSO) and climate change. Climate change is putting increasing pressure on many ecosystems, making them and the communities that depend on them for their livelihoods more susceptible strong El Niño events, such as the 2015/16 event.

Mangrove conservation has been proposed as a form of Ecosystem-Based Adaptation (EBA) to help protect livelihoods in the face of climate change, providing co-benefits for biodiversity and local communities. However, this strategy may be rendered ineffective if the impacts of extreme El Nino and La Niña events threaten the survival and functioning of mangrove systems and their socio-economic consequences. It is therefore particularly urgent to quantify the impacts of El Niño on mangroves and their socio-economic consequences on the local communities; the current El Niño event provides a transient opportunity to obtain these critical baseline data.

Colombia is being affected severely by El Nino. There is a dearth of data for coastal regions, yet the impacts of both El Niño and La Niña on coastal communities in areas vulnerable to both droughts and floods have been severe, with shortages of fish and degradation of mangrove systems. Mangroves provide a range of ecosystem services that support livelihoods, including provisioning services such as fisheries, wood, agriculture and transportation, and regulating services such as flood protection, sediment regulation, erosion regulation and carbon storage. The status of mangroves and their intimate link to human well-being and poverty alleviation provides a unique opportunity to quantify the broader impacts of El Nino events.

In partnership with Grupo Laera and INVEMAR in Colombia, we will quantify the impacts of the current El Niño event on mangroves in two contrasting mangrove systems in Colombia - La Boquilla, which is a relatively high energy system, facing the open sea, and Cienaga Grande de Santa Marta (CGSM), which is a low energy, lagoonal system. Working with our partners, we will collect empirical data on the status of the mangrove system and the following ecosystem services: fisheries, flood and erosion regulation and sediment regulation. We will combine these data with quantitative and qualitative data on the economic and social impacts of the current El Niño event, and supplement them with time series environmental data from a series of monitoring stations maintained by INVEMAR, the Colombian Marine and Coastal Research Institute.

We will derive economic values associated with key ecosystem services from the mangroves using a combination of market-based and spatial value transfer approaches. We will work with local community groups and stakeholders (via workshops) to develop and refine our models of ecological and physical properties of the mangroves into integrated ecological-economic models, and use a future scenarios-based approach to examine the ecosystem and livelihood impacts of various anthropogenic pressures and internal changes within the mangroves.

The work will enhance the environmental and socio-economic evidence base of the impacts of the current El Niño event in Colombia and, through the development of co-produced models, contribute to a better understanding of resilience of these systems and the livelihoods they support, to future El Niño events in the region.

The project will have a significant benefit for understanding the impacts of El Niño events on sustainability and livelihoods via its impact on ecosystem functioning and services in one of the most threatened habitats on Earth. This will inform future mitigation and adaptation strategies and build socio-economic resilience against future ENSO episodes.

The importance of managing biodiversity to ensure that ecosystems are resilient, continue to support livelihoods and contribute to poverty eradication is a central tenet of the Aichi Biodiversity Targets in the CBD's Strategic Plan for Biodiversity 2011-2020. Understanding the impacts of environmental change via impacts on biodiversity is also emphasised in national and international programmes, such as BioMERGE (USA), MarBEF (EU), and Future Earth (international). Through Solan's membership of the scientific committee of ecoSERVICES, a project of Future Earth, and his participation in IPBES, the research will be well placed to inform the IPBES Regional Assessment for the Americas (Decision IPBES 3/1 Annex V). The work will also link in with The Nature Conservancy's Coastal Resilience Program of the Natural Coastal Protection project, which is a collaborative venture to understand how natural ecosystems can and should be worked into strategies for coastal protection. We will also link with the Mangrove Capital project, a partnership between Wetlands International, The Nature Conservancy, Deltares, Wageningen University and several Indonesian partner organisations, which advances the restoration of mangrove forests as an effective strategy for ensuring resilience against natural hazards and enhancing economic prosperity. Links to Wetlands International and other relevant international organisations such as UNEP-WCMC will be enabled by the team's policy networks, and by the location of UNEP-WCMC in Cambridge.

The new information generated on mangrove dynamics and their potential role as EBAs will be particularly timely since Colombia has recently introduced ecosystem services into its biodiversity policy (MADS, 2012) and the first national mapping of ecosystem services for Colombia has just been completed (Rodriguez et al., Land Use Policy 42:609). At the national level, the project will therefore provide authorities with information to feed into sectoral adaptation plans that are already being developed, particularly in the areas of fisheries and agriculture; it will also inform the national and local environmental authorities in decisions on infrastructure developments, where impacts on key mangrove ecosystem functions are likely to occur. Significantly, it will inform the relevant authorities in design of early warning systems to reduce the impacts of droughts related to future El Niño phenomena and floods related to La Niña. Finally, at the local level, it will provide with information to the Colombian Municipalities to improve their Local Territorial planning.

The interaction between UK scientists and Colombian scientists, and the involvement of INVEMAR is the research is likely to generate further collaboration between both countries. The protective role of mangroves is understudied in the Americas; this research will set the baseline for further research that informs decision makers and donors across the region about the effectiveness and characteristics of mangroves as EBAs and their contribution to resilience and livelihoods.