In August 2005 Hurricane Katrina hit the Louisiana and Mississippi coastline of the United States, flooding New Orleans and causing catastrophic damage to coastal communities in both states. Katrina still ranks as the costliest storm in US history, inflicting an estimated US$81 billion in damages and causing 1,836 deaths.

Tropical storms and hurricanes are frequent along this coast, threatening both large metropolitan areas and small coastal communities, but research is showing that natural ecosystems such as coastal marshes play an important protection role.

As Katrina struck, Jean Lafitte National Historic Park and Preserve, south of New Orleans and Gulf Islands National Seashore, which lies south of the Mississippi coastal mainland, played a key role in the protection of coastal communities through their wetlands, marshes and barrier islands which absorbed some of the force of the storm surges.

As well as reducing the power of the waves, these parks also protected engineered hurricane protection levees (which border the park and metropolitan New Orleans), as well as the coastal communities of Mississippi that do not have these levees.

Restoring wetlands and other natural systems which have been damaged by human activity over the years is essential if they are to reach their protection potential. The US government is seeing the importance of this and directing funding towards such efforts.

'The US Congress has authorised funding to restore the Gulf Islands National Seashore at a cost of over US$ 400 million," says Mark Ford of the US National Parks Service Regional Office in New Orleans. 'This, plus the cost of restoration for Jean Lafitte estimated at over US$50 million is still a fraction of the economic losses caused by Hurricane Katrina and shows the wisdom of investing in nature. Restoration efforts are far less expensive than post-disaster repairs."

'The evidence is growing of the role of natural landscapes in reducing the impact of disasters. With climate change increasing the frequency of storms and hurricanes, we should work quickly to restore them, especially those near human settlements," adds Ford.