Coral Reefs Can Help Reduce Shoreline Erosion


Image: Healthy coral reefs don't just attract sealife but also can protect against shoreline erosion

 

Coral reefs in St. Vincent

During our survey of St. Vincent and the Grenadine Islands for the Catlin Seaview Survey, we saw coral reefs affected by continuous high-energy wave action, making the reef look like a barren ‘lunar-like’ seascape in some sections.

Coral reefs can act as an important barrier to protect adjacent coastlines from high-energy waves that can cause beach erosion, making shorelines retreat inland. For island communities like St. Vincent, where iconic beaches attract a bourgeoning tourist market, (Madonna, Bowie and Jagger purportedly own houses here) and a large proportion of the island’s infrastructure (roads, airports, buildings and tourism properties) is concentrated near the coast, the health of fringing coral reefs is of fundamental concern to all.

Coral fringing reefs often grow very close to the sea surface. Waves break and expend their energy on the reef, thereby lessening the effect on the adjacent coastline. Even a dead coral reef may continue to act as a breakwater for nearby beaches.

 

The danger of hurricanes

Since 1995, St. Vincent and the Grenadine Islands have experienced an increasingly active hurricane cycle. Hurricane Lenny in 1999 dramatically changed the contour of many beaches. Along the west coast of Mustique, the force of the waves from Hurricane Lenny broke apart offshore coral reefs, causing giant piles of coral rubble to amass that could be seen from shore.

There is often a time lag of several years before the effects of coral reef damage are seen on nearby beaches. If a reef is lowered by one hurricane, it may not be until the next tropical storm or hurricane that the reduced breakwater effect is seen through increased beach erosion. Wherever coral reefs exist, their health is of vital importance to adjacent beaches.

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