« October 2010 Table of Contents
Point of View: Invest in the Gulf's natural capital
Rowan Jacobsen and Michael Beck
October 01, 2010
Not long after the first European explorers encountered the Gulf of Mexico, word filtered back to the continent that along this exotic coastline, oysters grew on trees. This caught the European imagination. There was even a kernel of truth to it: The trees in question were mangroves, and oysters indeed did grow on the roots of these intertidal trees. More often, they thrived at the margins of the seemingly limitless marshes that stretched to the horizon, perched between sea and sky.
The Gulf really was a paradise of abundance. Where else do you have a river the size of the Mississippi draining a region as fertile as the Heartland into a well-enclosed body of water as warm as the Gulf of Mexico? This is why the Gulf has continued, despite the damage we have done to it, to produce seafood at astonishing rates. With its burgeoning populations of shellfish and finfish, it has been a natural engine of prosperity.
Key to the Gulf’s productivity are its marshes, the nurseries of the sea. Fed by the regular supply of sediment washed over them by the Mississippi River and its distributaries, the marshes have built up over the past 5,000 years into the vast network of estuaries we know today. Tucked safely into its marshes, these sea grass meadows, oyster reefs and other critical habitats form the base of the marine food chain. In fact, 97 percent of the commercial catch of fish species in the Gulf depends on its estuaries and their nursery habitats for survival. To take just one example, the Gulf’s famous shrimp — which account for 73 percent of the nation’s total shrimp harvest and hundreds of millions of dollars in dockside revenue alone — lay their eggs in the open Gulf, but then their hatched larvae head for the inshore salt marshes, where they live until they are ready to return to the open waters as adults. No salt marshes, no shrimp. No estuaries, no fish.
The animal most responsible for maintaining the integrity of these estuaries is the oyster. Oyster reefs are living breakwaters that protect the soft marsh shorelines from erosion and storm damage. They also serve as the condominiums of the sea, providing intricate habitat for many small and juvenile creatures that comprise the foundation of the Gulf food web. Studies show that the commercial value of the Gulf’s oysters (more than $60 million per year, about 67 percent of the nation’s total oyster harvest) is easily surpassed by the commercial value of the fish that need these reefs. When you add the reefs’ role in filtering and cleaning the Gulf waters and protecting the shores, their value is at least 10 times more.
There are few other places on Earth still like this. Worldwide, 85 percent of oyster reefs have been lost. They are the single most imperiled marine habitat. The oyster reefs of the Gulf are not merely the best in the nation; they are the best in the world, a global treasure. Yet even they are severely degraded. More than 50 percent had been lost before BP’s Deepwater Horizon oil spill.
The marshes, too, are in sharp decline. The Mississippi River levee system helps control flooding, but it also robs the marshes of the sediments they need to replenish themselves. The thousands of miles of canals dug through the wetlands by the oil industry in its search for new reservoirs further erode the marshes. Nearly 2,000 square miles of Louisiana have been lost so far. That’s 2,000 square miles of fish nurseries, shrimping grounds, storm buffers, recreational paradise and people’s homes.
Before the oil spill, scientists agreed that the only place on Earth offering a realistic opportunity for oyster reef restoration on a scale that could support a truly sustainable fishery was the Gulf of Mexico. They also agreed that comprehensive wetland restoration was vital to the future of Louisiana. But there had never been the political will for it. Now that the Deepwater Horizon spill has brought such attention to our southern coast, perhaps we can recognize it for the treasure that it is, and agree to the kind of
national response that has been needed for so long.
In the Mississippi Delta, we need to reengineer levees to divert a portion of river flow so that the valuable sediment can spill out of it. We need to rebuild the natural capital of the oyster reefs and harvest only the yearly interest, leaving the principle of the reefs untouched. These efforts will require many of the same workers displaced by the current spill. The cost will be significant. But the payoff for working toward true restoration in the Gulf of Mexico is four-fold: The creation of opportunity now; a tangible demonstration of hope for the future of the region and its people; enhanced resiliency to bounce back from future impacts such as storms; and the return of the region’s natural capital and productivity. This is the kind of deal that helps guarantee a community, a region and a nation’s long-term prosperity.
Rowan Jacobsen is the author of “The Living Shore: Rediscovering aLost World,” and the forthcoming “Shadows on the Gulf: A Journey Through Our Last Great Wetland.” Michael Beck, Ph.D., is senior scientist with The Nature Conservancy’s Global Marine Initiative.