Wetlands along the southern coastlines of the United States serve as natural speed bumps to approaching hurricanes by starving them of warm ocean water and creating physical barriers to surging flood waters. However, in the last 100 years, the construction of levees and canals has turned thousands of square miles of wetland habitat into open water. This video from NOVA scienceNOW explores the importance of these critical habitats and examines the damage Hurricane Katrina caused to one stretch of Louisiana wetland.