As Louisiana's wetlands continue to disappear at an alarming rate, a new study has pinpointed the man-made structures that disrupt the natural water flow and threaten these important ecosystems. The findings have important implications for New Orleans and other coastal cities that rely on coastal wetlands to serve as buffer from destructive extreme weather events.Scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science found that man-made canals limit the natural tidal inundation process in roughly 45 percent of the state's coastline, and disruptions from levees accounted for 15 percent.