The WaterMarks Interview

Dr. James “Jimmy” B. Johnston

Louisiana Coastal Ecosystems Science Coordinator and Spatial (Habitat) Analysis Director, National Wetlands Research Center, U.S. Geological Survey, Lafayette, LA

Dr. Johnston has been involved in land loss studies since 1978, when he was instrumental in developing the first land loss data for Louisiana’s entire coastal zone for the U.S. Fish and Wildlife Service.

WaterMarks: There have been land loss studies in the past. Why is the report Historical and Predicted Coastal Louisiana Land Changes: 1978 – 2050 so significant?

Johnston: This report gives us a thorough, detailed picture of the current status of coastal Louisiana and of its future trend. Primarily, it documents that conditions have continued to deteriorate, and that Louisiana is still losing tens of thousands of acres of coastal land every year. The report also prescribes that the best hope for recovery lies in immediately undertaking large-scale remedies. It depicts the urgency of the current situation in solid scientific facts and figures.

WaterMarks: What was your response when you first saw the study results?

Johnston: To tell the truth, I was surprised — shocked, actually— by the numbers. I thought 25 years of improved coastal management practices and restoration efforts would produce a dramatic decline in land loss rates. They didn’t. Louisiana continues to lose an alarming amount of land every year. In fact, Louisiana accounts for 90 percent of the total coastal marsh loss within the continental United States, up from 80 percent 15 years ago. If nothing further is done to reverse or control the current trend, by the year 2050 a third of the entire coast of Louisiana will be gone.

WaterMarks: But the report shows that the rate of land loss is decreasing. Isn’t that good news?

Johnston: Unfortunately, it’s not good news at all, because it indicates just how badly Louisiana’s coast has already deteriorated. Between 1990 and 2000, the rate of coastal land loss, about 24 square miles a year, was two-thirds of what it was between 1978 and 1990. But this decline in the rate is just an illusion— simply the result of already having lost large areas of land. Land that has washed away cannot be recounted. That leaves less land, which shows a lower rate of loss. In some areas, such as in the Barataria and Terrebonne Basins, just west of the Mississippi River, land loss rates have continued to increase. By 2050, up to 80 percent of all land loss in coastal Louisiana is likely to have occurred in these two basins.

WaterMarks: The study predicts that by 2050 over 500 more square miles of Louisiana will disappear. Is this a realistic projection?

Johnston: Yes, we should expect to lose that much land, if not more. We’re getting very good at analyzing data and understanding the interaction of different causes of land change. The study includes precise information about past loss and current conditions, giving us a solid basis for identifying trends and projecting future changes. If there’s any inaccuracy , I think it’s in overestimating the amount of land gain that we may see. Presently we’re operating the diversions at Caernarvon and Davis Pond at lower capacities, reducing their potential for building new land. Also, we’re assuming that conditions will stay roughly the same as they have been over the past decade or so. However, land loss could increase for a number of other reasons, such as rising sea levels or more frequent hurricanes.

WaterMarks: We’ve been investing in projects to address this crisis for years, and yet the situation has worsened. Have we wasted our money?

Johnston: Not at all. The projects we’ve put into place so far are designed to address conditions at specific sites. Already these smaller projects have created or protected thousands of acres of coastal wetlands. They’ve provided us with information about how marshes respond to different restoration strategies so that we can refine our techniques.

WaterMarks: Can anything really be done to reverse Louisiana’s land loss?

Johnston: The study indicates that only bold strategies will be effective in addressing the crisis of land loss in Louisiana. Coastwide, we need to look at large landscape-scale management. Ultimately, the solution lies in the Mississippi River, in accessing its course and load of land-building sediments and restoring its historic role in rejuvenating the wetlands.

WaterMarks: When you talk of a landscape-scale management plan, you’re talking about a huge expense. Is it worth the money involved?

Johnston: If we do nothing further to stem the loss, 2,400 square miles of Louisiana will be under water by 2050. Just at the local level, the worth of property, commerce and infrastructure is many times more than the estimated $14 billion it will take to prevent the crisis. That doesn’t even consider the value of intangible things, like southern Louisiana’s history, culture and heritage, which would vanish with the land. Nationally, who can be complacent about losing a third of a state’s coastline? If a third of coastal Massachusetts or a third of Florida’s coast disappeared, wouldn’t the country mobilize to reclaim it?