For much of our recent history societies have viewed mangroves as swamps, health hazards, and only good for draining and developing. Yet, fast forward to the present day and it is widely acknowledged that mangroves are anything but wastelands. In fact they provide highly valuable services such as coastal protection, habitat for wildlife, breeding grounds for fisheries, and carbon storage.
This is especially the case in developing Pacific nations where mangroves contribute enormously to the economy and wellbeing of local people and cultures.
Despite their value, they are an ecosystem under threat, with up to a third of mangroves around the world being cleared for coastal development and aquaculture since 1980. What is left is facing pressure from other factors including climate change and rising sea levels. The resources available to save this precious ecosystem are scarce so it is important to invest them wisely.
CEED researchers have shown a way to help prioritise investments in mangrove conservation in a way that takes into account the different values of the ecosystem services that individual mangroves provide across a management area. They demonstrated the value of this approach by mapping multiple ecosystem services being provided by Fiji's mangroves and their relative value across the country. Their new approach could prove vital to policy makers and funding organisations seeking specific policy outcomes when planning investments in mangrove ecosystems.
"Incorporating the values of the services that ecosystems provide into decision making is becoming increasingly common in nature conservation and resource management," says Scott Atkinson, the lead author on the research.
"However, with limited funds for conservation, identifying priority areas where investment efficiently conserves multiple ecosystem services becomes incredibly important.
"We showed this could be done by mapping four mangrove ecosystems services (coastal protection, fisheries, biodiversity and carbon storage) across Fiji. Using a cost-effectiveness analysis, we ranked mangrove areas for each of those four services, where the effectiveness was a function of the benefits provided to the local communities, and the costs were associated with restricting specific uses of the mangrove."
Researchers found that different areas of mangroves around Fiji provided different values of the individual ecosystem services. Spatially explicit mapping such as this can help decision-makers direct funding to localities that best meet the funding objectives. For example, financing for disaster-risk reduction and climate adaptation (eg, from the Green Climate Fund) can be directed toward mangrove areas with the highest coastal protection services. Biodiversity funds (eg, from the Global Environment Facility) can be directed towards areas with the highest potential to conserve species.
"Presently in Fiji, funding for biodiversity has been 'bundled' with funding for climate adaptation and sustainable land management," says co-author Stacy Jupiter of the Wildlife Conservation Society in Fiji.
"As a consequence, this funding has been directed to some of the most degraded habitats in the country. This might improve sustainable land management but it's likely a major lost opportunity for effective biodiversity financing and conservation. This example shows why it's important to distinguish between areas that provide differing levels of ecosystem services."
The researchers also believe their approach might help in the designation of 'no-go zones' for development in Fiji.
"Our national-scale assessment might allow for guiding the selection of the highest priority areas for each ecosystem service where development and extractive activities are not allowed," observes Atkinson.
The researchers noted that such mapping exercises need to deal with issues of poor data availability and associated equity concerns in rural areas, but believe their approach provides a significant improvement on existing approaches that either deal with a single ecosystem service, ignore them all together, or do not account for the spatial differences in ecosystem services across entire management areas.
Reference: Atkinson SC, SD Jupiter, VM Adams, JC Ingram, S Narayan, CJ Klein & HP Possingham (2016) Prioritising Mangrove Ecosystem Services Results in Spatially Variable Management Priorities. PLoS ONE 11(3): e0151992. http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0151992
Image: Scott Atkinson. Fishing boats tied up to a mangrove near Suva, Fiji. Mangroves provide a range of valued ecosystem services. New research is enabling managers and policy makers to take this into account in their decision making.