The Daily, Global Disaster of Shoreline Erosion
While in Grenada, I met Dexter Miller on Petit Martinique (one of that country’s islands). We met on one of the few flat pieces of land on the island. Almost all his town’s livelihoods and lives happen on that one piece of land. Fishing is their main income, and the ports and docks are right there; boat-building is the second biggest income generator, and they make the boats right on this one strip of land, which also contains the town’s store and gas station; and this area also doubles as the soccer field.
But the shores of his town — this one flat piece of land — have begun to erode rapidly. And even more rapidly in the past few years. This land loss is not about the future of intensifying storms and sea-level rise; nor is it even about past storms like 1999′s Hurricane Lenny (“Wrong Way Lenny”), which everyone on the island still remembers vividly. The erosion is happening now with no storm in sight — we watched it biting in and taking away part of their shore every day. This is the daily disaster.
What’s behind this increasing erosion? Past sand mining certainly contributed to it — but the residents stopped that mining. What the erosion is likely most about is that the fringing reefs of Petit Martinique are dying. What few are recognizing — even in the conservation community — is how drastically that fringing-reef breakdown increases the wave energy hitting shores every day.
Mere inches of lost fore-reef depth (either because reefs are not growing or sea levels are rising) means substantially greater wave energy transmitted over the reefs and hitting shorelines (Field et al. 2011). This increase in wave energy is an engineering fact, well worked out for artificial breakwaters around the world.