Ensuring coastal resilience for The Bahamas
A new Stanford-led study, with support from The Nature Conservancy (TNC) and other partners, provides information that policymakers, community leaders and development banks need for post-disaster recovery and storm preparation in The Bahamas. The findings are being used by the Bahamian government and others to pinpoint key areas where investment in natural ecosystems could support a more storm-resilient future.
As new storms gain strength in the Atlantic, residents of The Bahamas continue recovering from Hurricane Dorian’s battering this month.
Villages were destroyed, streets flooded and a yet-unknown number of people died in the unprecedented cyclone.
The losses were grim validation of a new Stanford-led study on coastal risk throughout the country. The study predicts a tripling of storm-related damage if protective ecosystems such as coral reefs and mangrove forests are degraded or lost.
The findings, published in Frontiers in Marine Science, are being used by the Bahamian government, development banks and local communities to pinpoint key areas where investment in natural ecosystems could support a more storm-resilient future.
“Climate change is forcing coastal nations to reckon with a new reality of disaster management and to rethink the business-as-usual development model in order to survive. In The Bahamas, the islands hardest hit by Hurricane Dorian – Grand Bahama and Abaco – were those our research identified as the most at-risk to coastal hazards in the whole country,” said Jessica Silver, lead author on the study. “Understanding and mapping at-risk areas and their natural assets is a first step in changing development norms.”
Silver and other researchers at Stanford’s Natural Capital Project have been working in The Bahamas for five years alongside TNC, government partners, Bahamian scientists and the Inter-American Development Bank (IDB). Together, they have modeled coastal hazards and the role nature plays in reducing risk in the country.
“Governments have to make difficult decisions on where to invest their resources in the protection and restoration of coastal habitats,” said Steve Schill, lead scientist for TNC in the Caribbean. “Science-based models offer much-needed assistance in prioritizing the coastline and providing insight into where coastal habitats are most likely to reduce the impacts from flooding. When you couple this analysis with where communities are most vulnerable, the decision on where to invest becomes more impactful.”
The work for this study is part of a growing body of research showing that natural defenses can, in many places, represent more climate-resilient alternatives to traditional built shoreline protection – like seawalls and jetties – which are expensive to build and maintain.
For example, coral reefs weaken storm surges by reducing the energy of waves. The waves that do make it past the reefs are buffered by mangrove forests and seagrass beds, which also secure sand and sediment to prevent shoreline erosion.
By the time a storm reaches homes and infrastructure, the island’s environmental barricades have gradually lessened its strength.
These natural defenses are also a local source of sustenance and economic security. Healthy coastal habitats support abundant fisheries — a resource especially important in the aftermath of a storm, when food supplies are low. Thriving marine areas help communities regain their financial footing through key industries like tourism and commercial fishing.
Local decision-makers often lack basic information about where and how to invest in critical risk-reducing ecosystems. The research team combined information on storm waves and sea-level rise with maps of coastal habitats and census data to close this information gap.
The researchers assessed the risk reduction provided by coral reefs, mangroves and seagrass along the entire coast of The Bahamas using open source software developed by the Natural Capital Project. They looked at current and projected sea-level rise scenarios, identifying the most vulnerable groups of people and where they live.
“Our results show that the population most exposed to coastal hazards would more than double with future sea-level rise and more than triple if ecosystems were lost or degraded,” said Katie Arkema, co-author and lead scientist at the Natural Capital Project.
“We see that on populated islands like Grand Bahama and Abaco, natural habitats provide protection to disproportionately large numbers of people compared to the rest of the country. Without them, the destruction from Dorian could have been even worse.”
The study equips the Bahamian government and supporting development banks with clear, actionable information to guide future investments in natural ecosystems.
It shows where nature is providing the greatest benefit to people and can help decision-makers understand where and how targeted conservation and restoration projects could support coastal resilience. In the aftermath of Hurricane Dorian’s destruction, the Stanford team has been in close communication with their Bahamian co-authors, who are already using these results to call for strategic investments in nature. As they begin to recover and rebuild, the researchers have their Bahamian colleagues in mind.
“It is critical that all stakeholders, government, private sector and civil society use studies such as this one to guide decision-making about rebuilding, in the wake of Hurricane Dorian and other natural disasters,” said Shenique Smith, director of TNC in The Bahamas.
“TNC has been an advocate, and will continue to support incorporating natural systems into sustainable development to assist in building resilience in our coastal communities and infrastructure.”
“We hope, in some small way, that the results of this study will help our friends and colleagues build a more resilient future for The Bahamas,” Silver said. “And, we hope that other countries will look to The Bahamas as a beacon of progress and fortitude in the face of climate adversity.”