for National Geographic News
Hurricane Katrina destroyed large swaths of wetlands and fragile barrier islands off the coasts of Mississippi and Louisiana, scientists say.
The damage is drawing renewed attention to the role that human activity has had in weakening the coastal ecosystem. It also has raised the stakes on an ambitious 14-billion-U.S.-dollar restoration proposal that has been awaiting approval from the U.S. Congress since long before Katrina struck.
Aerial surveys show that Louisiana's barrier islands have sustained especially heavy losses from Katrina's scouring winds and waves.
Some island chains, like the delicate, crescent-shaped Chandeleur Islands off the southeastern coast, scarcely exist today.
"Right now they are essentially gone,'' said Robert Young, a coastal marine geologist with Western Carolina University in Cullowhee, North Carolina.
Although scientists have only begun to analyze the damage along the coast, their initial assessments are grim.
``I have never seen anything like it," said Young, who has been surveying the coast by air. "This is the most significant water-impact storm that I have seen, and I've been doing this for 20 years."
"Humans Are Partly Responsible"
In addition to their vital roles in the Gulf ecosystem, the barrier islands and wetlands also play a crucial part in protecting coastal communities from future hurricanes.
``The damage [from Katrina] may have been worse if those islands weren't there," Young said. "They may not have reduced the storm surge level, but they did reduce the wave impact on the inner shore.''
Now with many of the islands reduced to sandbars and with acres of marshes washed out, those natural defenses are gone.
And scientists are quick to note that the damage is not all Katrina's fault.
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