By Kathryn Cannon
On August 29, 2005, Hurricane Katina ripped through the coastal wetlands and into the city of New Orleans. Most people remember only how New Orleans and the surrounding areas were affected but not how the coastal wetlands, barrier islands or marshes were also impacted.
“After hurricane Katrina we lost several thousand acres of marsh on several of our refuges,” said James Harris, Senior Wildlife Biologist for the Southeast Louisiana Refuges Complex. “It was converted from emergent marsh with vegetation and various forms of wildlife to open water.” Our coastal wetlands are important to our wildlife and even our way of living. Through coastal restoration programs funded by the state and other federal entities, the USF&WS tries to preserve and rebuild our coastal wetlands through various means.
The Southeast Louisiana Refuges Complex is a branch with the United States Fisheries & Wildlife Services. Harris specializes in restoration of coastal habitats including marsh and barrier islands. He has constructed numerous small-scale sediment diversions at Delta NWR, which is one of the 8 National Wildlife Refuges covered by the Southeast Louisiana Refuges Complex. They have also restored marsh using dedicated dredge disposal within the complex.
Off the coast of Louisiana, there are barrier islands, marshes and coastal wetlands. Barrier islands are a coastal landform of offshore deposits of sand or sediment. They are a long and relatively narrow islands running parallel to the mainland. They serve to protect the coast from erosion by surf and tidal surges, and act as a barrier to storm surges from hurricanes. However, every 38 minutes, another football field of wetlands disappears into the sea, taking with it nature’s best storm protection and water filter, as well as a cradle for sea life.
The Gulf of Mexico’s coastal wetlands have an abundance and variety of wildlife. They are home to 132 federally listed species, 95 of which are endangered. The Gulf region provides habitats for millions of waterfowl, shore birds, song birds, herons and egrets. The coastal wetlands are home to hardwood forests, cypress swamps, coastal marshes, estuaries and barrier islands.
If Louisiana continues to lose her barrier islands and coastal wetlands, it will have an enormous effect on our way of life. “There are a huge number of species negatively impacted by the loss of coastal habitats,” Harris commented. We use these habitats for cultural recreation such as fishing, photography, hunting, education and wildlife observation. “Then we get into what’s really important to a lot of Louisianans – the seafood. The seafood industry is the main source of income for many south Louisianians,” Harris said. “The coastal habitats are extremely important as they serve as nursery areas for shrimp, fish, blue crabs etc., and it would not only impact us, but the nation as a whole.”
The million dollar question is how we stop the excessive land loss of our coastal wetlands, marshes and barrier islands without ultimately causing further damage to our already fragile ecosystem. The USF&WS is creating ways to lessen the damage done by hurricanes, erosion and rising sea levels by using a process called sediment diversions. River diversions are one of the fundamental tools available for coastal restoration in Louisiana. Under certain scenarios, they offer an efficient and effective means of building new land, provide a substrate for wetland growth and vegetation regrowth, and provide an opportunity for enhancement of ecological diversity. “We are getting better, if you will, at designing projects and designing restoration to take advantage of the natural processes that either sustains what we’ve built or makes it more resilient to storms,” Harris said. “So that a storm may damage it, but hopefully it won’t completely wipe it away again.”
Harris demonstrated on Google Earth how they use the program to look backward and forward over a period of years to see how the land was and how it develops via satellite photos. When they create a sediment diversion they use Google Earth to map out where the diversion will go and view the progress that is made over a period of time.
The coastal marshes of Louisiana are extremely important both from the natural resource side and from the human side. “These areas are culturally important and that can’t be discounted when you’re talking about people. People are most comfortable when they have a sense of place – a sense of protection if you will – and these marshes and barrier islands and all these habitats provide that,” Harris said. “It’s what protects us. It is what not only protects our livelihood, but it protects our houses and infrastructure; so it’s tremendously important.” If we have the ability to make the environment better, we should do it by any means necessary.