The catastrophic 2017 hurricane season provided ample demonstrations of the increasing vulnerability of Caribbean populations and infrastructure to natural disasters. Researchers at UC Santa Cruz and the Nature Conservancy have now measured the protective role of coral reefs and field-tested a solution that reduces coastal risks by combining innovative engineering with restoration ecology.
Working in Grenville Bay, Grenada, the researchers showed that degradation of coral reefs is directly linked to shoreline erosion and coastal flooding in parts of the bay. The study, published February 1 in the Journal of Environmental Management, also evaluates one of the first uses of reef restoration as natural infrastructure specifically designed to reduce risks to people and property.
Investigating the link between healthy reefs and shoreline stability, the researchers found that Grenville's healthy reefs keep more than half of the bay's coastline intact by reducing the wave energy arriving on shore. In contrast, severe reef degradation is linked with chronic coastal erosion in the northern section of the bay, where the shoreline is disappearing at a rate of nearly two feet every year.
In an attempt to adapt, villagers have built makeshift barriers with tires and driftwood to slow the erosion threatening their homes, but these efforts have been largely unsuccessful. The reef restoration project was designed to enhance both the ecological functions of natural reef habitat and its protective effects.
"We are able to apply coastal engineering tools and models to support reef science and management. Ours is one of the first studies to directly show with evidence from the field sites and engineering models the impacts of reef loss on shorelines," said lead author Borja Reguero, a researcher at the Institute of Marine Sciences at UC Santa Cruz. Read More