Of Hurricanes and Habitat: Ten Years After Katrina

Ten years ago this week, the world watched in horror as Hurricane Katrina bore down on the Gulf Coast. In addition to the tragic loss of life, property damage, and economic toll, the storm wreaked havoc on some of the nation’s most important habitats for birds and ocean life.

The low-lying barrier islands in the northern Gulf of Mexico took some of the worst of the damage. The Chandeleur Islands and Cape Breton Islands stretch like a comma between the Mississippi Delta and the coast. Together, they form Breton National Wildlife Refuge, which was designated by Teddy Roosevelt as the country’s second national wildlife refuge to protect the seabird colonies that nest there. Katrina, along with Hurricane Rita which took a similar path just a month later, tore huge gaps in the fragile stretches of beach and marsh. The Breton Islands lost 70 percent of their land area to the erosion and storm surge, and the Chandeleur Islands lost 50 percent, essentially getting “diced” into dozens of smaller islands separated by open water.

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The coastal marshes and wetlands in the area were devastated as well. The U.S. Geological Survey estimated that 217 square miles of Louisiana’s coastal wetlands were converted to open water following Katrina and Rita, with losses to both coastal saltmarshes and inland freshwater marshes – two very important habitats that are home to countless birds, fish, crustaceans and shellfish.

Damages extended inland as well. Bottomland hardwood forests along the Pearl River, located about 40 miles northeast of New Orleans on the Louisiana-Mississippi border, are an important stopover for migratory birds. This area took a direct hit from Katrina at Category-3 strength. The 120 mph winds had a devastating effect: at one long-term study site, 65 percent of the trees were damaged or blown down. Interestingly, damage was less severe at study sites that were dominated by bald cypress trees, which are more tolerant to wind and flooding.

It would be bad enough if the tragic events of August and September 2005 were a one-time disaster in the history of the Gulf Coast. Unfortunately, however, they played out against a backdrop of ongoing loss of coastal wetlands – averaging 34 square miles per year – resulting from climate change-induced sea level rise and a lack of sediments that historically would naturally replenish these areas, but are now trapped behind dams, diversions and other structures on the Mississippi River. And in 2010, the Deepwater Horizon disaster dealt another horrific blow to the region.

The region is fighting back, however, working to restore and preserve its unique habitats in the face of these threats. Louisiana’s Coastal Protection and Restoration Authority, using disaster recovery assistance as well as Deepwater Horizon settlement money, has worked to restore more than 25,000 acres of coastal habitat and rebuilt 45 miles of barrier islands. Their projects include installing living shorelines and oyster reefs, restoring and improving marshes, closing breaches in barrier islands, protecting coastal forests, and re-establishing the natural sediment flow that have been disrupted by development along the Mississippi.

Some wonder, of course, if all of this is a losing battle: are we just marking time until rising seas or the next major storm undo all that has been accomplished over the past ten years? It is true that our warming climate puts the region more at risk of both of these possibilities. However, such a view neglects the simple truth of the benefits these projects are already providing to the region, both as habitat and as buffers that protect inland communities from the hazards of storm surge and coastal flooding. According to one study of the value of coastal restoration projects, every $1 million invested in these activities creates about 17 jobs, roughly twice what the same investment in oil and gas development produces. And when that is added to the values these projects produce in reducing hazards, absorbing nutrients and pollution, enhancing property values, fisheries, and recreation, and restoring and protecting our coasts, the benefits become 15 to 20 times greater than the cost. And since fish and wildlife, including millions of resident and migratory birds, depend on the wetlands of the Gulf Coast, giving up on these habitats is not an option.