Louisiana marsh restoration has failed

摘要

For two decades, fresh water from the Mississippi River has been diverted into Louisiana's shrinking coastal wetlands (pictured) in an attempt to restore them, but three such projects have failed to increase vegetation or marsh area. Moreover, the diversions have raised the marshes' risk of suffering hurricane damage. Michael Kearney at the University of Maryland in College Park and his team analysed satellite images collected between 1984 and 2009 for three of the longest-running diversion projects. They found that most new plant growth consisted of floating plants and algae rather than deep-rooted marsh plants that hold soil in place. For one of the diversions, Hurricane Katrina destroyed the most vegetation in zones that received the most direct input of fresh water.