September 9, 2008

Ultimately, Nature Will Be the Winner of Battle of the Coastline


The recent visit by Tropical Storm Fay reminds us that the First Coast is subject to change at any time. Nature doesn't care where we place property boundaries or homes and may change the landscape without notice. What we view as permanent is just one frame in the story of the coastal environment. Beaches erode and rebuild in predictable ways, never when or where we wish.

In this era of global climate change and rising sea levels, we should expect that natural beaches will erode. We can build beaches back or armor them, but that will not alter the long-range pattern of beach change. Ultimately, nature will win the battle of where the beach will end up.

Many coastal residents were surprised by the level of water driven into the St. Johns River by Fay, a relatively small storm, and by the level of standing water throughout the landscape. Nature had posted warning signs everywhere and we ignored them at our peril. Black soil revealed during construction signaled standing water happens there. Trees with roots above the soil suggested that structures placed there should be adapted for flood conditions, just as were trees that once inhabited the area. Modern development is replete with ignorance when it comes to reading nature's warning signs.

Natural resetting events such as hurricanes and floods destroy natural communities too. Sediments stirred up by wind and waves flush downstream and cover up oyster beds, while streams clogged with leaves and debris are swept clean by strong currents. Sea turtle nests are washed away and a generation of young destroyed, and trees that have survived for decades in swamps now lie broken on the swamp floor, leaving scars in the swamp canopy where they once stood. Despite all of these losses, these species will survive and flourish as long as humans do not interfere with the natural process. Sea oats will reappear and sea turtles will arrive next year to crawl up the beach and lay eggs, as long as we leave nature alone. Only seawalls and sandbags deter the process. All of our coastal species have thrived for thousands of years through hundreds of large-scale resetting events.

In fact, there are many benefits to these events that are not apparent. Excess nutrients were washed offshore by Fay and may fuel algal growth far offshore, nurturing offshore fish stocks. Sediment thrown onto marshes and swamps will build these wetlands, so they can maintain themselves in the face of sea-level rise. After every resetting event, there is always a rebirth. Species rarely seen suddenly appear and re-colonize damaged beaches and swamps and at sediment covered oyster beds, a flush of new worms and crabs will mold the environment so that it will again be suitable for oysters. This is the Florida we love and want to preserve for future generations.Courtney Hackney is the director of coastal biology at the University of North Florida.

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