P!Nterview: Wetlands Vital to Healthy Coastal Communities
Gulf of Mexico
Bill Finch, Director of Conservation and External Affairs with The Nature Conservancy in Alabama, explains the role that wetlands play in mitigating the effects of major storms, and how the Gulf oil spill might adversely affect those ecosystems.
Q: In coastal communities along the Gulf of Mexico and Eastern Seaboard, how do wetlands help mitigate the effects of major storms?
A: Marshes may play their most critical role in protecting shorelines day in and day out. Most shoreline erosion in the U.S. is the result of daily erosion. A three-foot high wave, for example, can easily knock down a sturdy brick wall, and even waves in the 1- to 3-foot range will clobber a bare shoreline. Thick marsh grasses bend with those waves, dissipating the energy, so that the waves have no energy left by the time they get to the hard shoreline. When you lose those marshes, on the other hand, you not only lose that dampening effect, you also effectively increase the water depth near the shoreline. And the greater the water depth, the bigger the waves can get. So big waves get closer to the shoreline, multiplying the damage. Loss of marsh grasses and oyster reefs may be a primary culprit in day-to-day shoreline losses approaching 15 feet a year (!) in places in Mobile Bay. Similar or greater rates are noted at multiple points in the Gulf and on the Atlantic Coast More