I read with great interest Amy Wold’s front-page article Sunday, Aug. 28, titled “Help or Harm,” detailing a report by LSU’s Eugene Turner and others questioning the benefits and land-building capacity of Mississippi River diversions.
Turner and his collaborators from the University of Maryland state they studied diversions at Caernarvon and Davis Pond and the siphon at Naomi and determined, because of an over-abundance of nutrients and lack of sediment, diversions are weakening coastal marshes.
Those claims are countered in the article by several of Turner’s contemporaries, including John Day from LSU’s Department of Coastal and Environmental Science, who say Turner’s findings are nothing new and some very healthy marshes are growing in the outflow areas of all of the diversions in question.
The Louisiana Wildlife Federation adopted a resolution this year urging more time and effort be devoted to studying diversions to better understand impacts and help coastal policymakers and scientists design projects as restoration efforts move forward.
Therefore, Turner’s critiques of the diversions are appreciated. The more we know about how coastal marshes are responding to projects intended to restore them, the better.
However, much of the scientific and visual evidence of what is happening near these diversions favors the opinion of those who countered the study.
I’m not a scientist. I’m an outdoorsman who cares deeply and has spent the past 30 years watching Louisiana’s marshes wash away and the last decade working with and listening to scientists and lawmakers working to restore our coast.
If Caernarvon is not building land, why did I see acres of new marsh in its outfall area last week, an area that was open water less than three years ago? If Davis Pond is weakening coastal wetlands, why did researchers find healthy cypress trees with rapid growth rates in its outflow area last year, an area that had historically been devastated by cypress-killing saltwater intrusion?
If diversions aren’t building land, why is there a new island emerging near the West Bay Diversion in Plaquemines Parish? If the nutrients in the Mississippi watershed are hurting, why are the Wax Lake Outlet, a diversion near the mouth of the Atchafalaya River, and the Atchafalaya Delta building acres of healthy wetlands?
Wetland loss plagues Louisiana’s entire coast. Marsh is washing away and sinking in Lafourche and Terrebonne parishes in areas nowhere near diversions. Vast areas of open water devoid of vegetation and fisheries and wildlife habitat remain.
At Caernarvon, Davis Pond, West Bay and Wax Lake, there is abundant vegetation and habitat, new land is emerging and there is the promise of more to come. It doesn’t seem hard to determine the better option.
coastal outreach coordinator, Louisiana Wildlife Federation