The WaterMarks Interview

Mark Schexnayder

Mark Schexnayder serves as a regional coastal advisor for fisheries in the Louisiana Sea Grant College program and the Louisiana State University Agricultural Center. He has also worked as director of the Marine Biological Lab on Grand Terre and as manager of the state crustacean program. He is shown in the photograph with his daughter Ava Eugenie, fishing in New Orleans City Park.

WaterMarks: Many planners argue that diversions are the only option available to save Louisiana's coastal wetlands. Are diversions really the answer?

Schexnayder: While we would all like to find a silver bullet, there just isn't one out there. And as powerful as they are, diversions are only one tool in the toolbox. Protecting what's left of Louisiana's coastal wetlands is going to require multiple, complex and expensive solutions.

WaterMarks: So diversions have their limitations.

Schexnayder: We tend to talk about diversions as if they were all the same. But diversions range from small siphons moving water at 250 cubic feet per second to proposed structures with the capacity of 200,000 cfs. So it's not so much a case of limitations as a matter of matching the right diversion to the project. In some cases, a series of small siphons might be a better fit than one large structure.

WaterMarks: I've heard you use the term reintroductions instead of diversions. Why?

Schexnayder: Diversions imply that we're changing a natural process, taking something away from the river. The facts are just the opposite. Breaching a levee restores a natural process of flooding that has always been part of the river. We're reintroducing water to wetlands in a way that replicates what happened before the levee system was built.

WaterMarks: But isn't the river is full of chemicals and fertilizers that will damage the wetlands?

Schexnayder: Some people worry that the Mississippi is really a kind of toxic soup that will kill off our wetlands rather than restore them, but water quality testing has shown that the river is remarkably free of toxins.

WaterMarks: So you're not worried about toxicity at all?

Schexnayder: Not at all. The real concern has been about excessive nutrients, and that's not been a problem to date. Nutrients themselves aren't toxic. Coastal wetlands assimilate nutrients rapidly -- in fact they respond by actually increasing their capacity to utilize them. Additional nutrients eventually express themselves further up the food chain as more shrimp, more fish, more birds and so forth. Even the so called"toxic" blue-green algae are an important food to many estuarine organisms.

WaterMarks: What about diversions' effects on fisheries? Don't oyster fishermen oppose diversions?

Schexnayder: The short answer is no. Oystermen have long recognized that fresh water improves oyster production. If we can return to more traditional salinity levels it'll be a big positive for oystermen in the long term. It'll eliminate the cost of improving oyster beds higher in the estuaries and reduce the dangers from pollution. And most importantly, oyster production will increase significantly.

WaterMarks: Isn't there a "Yeah, but ." here?

Schexnayder: The problem is that we are talking long term. The data we have show that the first two years after a diversion becomes operational can be the most disruptive. After that the bands of fresh and brackish water expand and oyster production begins to increase well beyond what it was before the diversion. We need a bridge for the fishing industry that will take us over the short-term problems and get us to the long term advantages. It's critical that some form of reasonable compensation for losses, in addition to the oyster-lease relocation program, be included in our thinking about diversions. We need to reach out and involve user groups like oystermen, commercial and sport fishermen -- not blame them. They could become a powerful force in the effort to save coastal wetlands.

WaterMarks: You emphasize the difficulty and complexity of really addressing the problem of coastal wetlands loss in Louisiana. How hopeful are you about the future?

Schexnayder: I'm concerned that coastal wetlands loss will always be a Louisiana problem -- that it won't ever become a priority for this nation and we won't ever have the dollars to seriously address the issues. But I'm also very concerned that if coastal wetlands loss does become a national priority, it will be because Louisiana has suffered a catastrophe -- one costing significant loss of life and billions of dollars in damage. My hope is that we have the foresight as a nation to act now rather than react to a disaster later.