Sea level rise could wipe out Texas fisheries’ ecosystem

The wetlands of the Texas coast — our most important coastal ecological system — are in danger of eradication from sea level rise. The science is clear. They will be gone if we don’t do something about it, and there are things we can do, but we need to get on it.

Our coastal wetlands exist where water and land meet. They thrive when high tide covers plants’ roots, which become dry again during low tide. They can survive several days of high tide and inundation, but they will suffocate if the water stays up for months and years. That is what science indicates is happening now and will worsen into the future.

Many may ask, why should I care? What difference does it make to me if these coastal wetlands continue to exist or not? And the simple answer is, the fishery of the Gulf of Mexico depends on these coastal marshes. They are the nurseries of the coast.

Each acre of marsh produces thousands of white and brown shrimp which are excellent to eat, and they support our state’s commercial fishery. The same is true with blue crab and flounder, which also use nature’s nursery.

Perhaps more important to many Texans is the recreational fishery of the coast. Redfish and speckled trout are higher predators in the bay food chain, and they feed on the shrimp and smaller finfish produced by the marsh. Along with seagrass, which is prominent in the southern portion of the Texas coast, these marshes are the key to coastal recreational fishing. No marsh, no sea-grass, no fish. It’s that simple.

It is hard for me to imagine a Texas coast without wetlands. Near Rockport, the only wild flock of endangered whooping cranes relies upon these marshes, where they feed upon blue crabs. And literally thousands of other fish-eating birds rely on these marshes, contributing to the wonder of the coast.

The politics surrounding climate change can be daunting. But concern about the future loss of our marshes is not about attacking any industry or anyone’s livelihood. Rather, this is a call to action for those concerned about the coastal marshes, about recreational and commercial fishing, about coastal birds. We must come together and act now to protect our future.

So what can be done? Living shorelines can be constructed to protect these marshes from erosion forces and to help them trap sediment that is needed to keep up with sea level rise.

These living shorelines are made of rock or concrete and are constructed about a hundred feet or so on the bay-side of the marsh. These structures are then seeded with oyster spat to generate oyster colonization. Once established, the oysters will grow and rise with sea level, representing a form of nature-based engineering.

These living shorelines are not cheap. They cost approximately $2 million per mile, and we need hundreds of miles of living shoreline to protect the 400,000 acres of Texas coastal wetlands. To finance these living shorelines, our thinking about economy and nature must change, and that change is currently well underway.

It is well known that marshes perform many functions for us, in addition to providing a nursery for shrimp and crabs and flounder. Marshes are very effective at capturing carbon dioxide from the atmosphere and storing it in the marsh mud.

Today, there is an emerging market where companies that emit carbon dioxide pay landowners for removal and storage of carbon dioxide by soil, forest and coastal marsh systems. Carbon credits also can be issued for the protection of the carbon that is currently stored in the marsh mud and that would be released when the marsh erodes and disappears in the future.

Our coastal industries could play a major role in creating the living shorelines we need while helping themselves as well. It’s a win-win solution.

So the next time you drive to Galveston and see those beautiful marshes protected on each side of the causeway, enjoy them. If we don’t protect them today, they might not be there in the future.

Jim Blackburn is a faculty scholar at Rice University’s Baker Institute for Public Policy, a professor in the practice of environmental law in the Civil and Environmental Engineering Department at Rice University and a practicing environmental lawyer with the Blackburn & Carter law firm in Houston.