Last week, we reviewed Benh Zeitlin’s Beasts of the Southern Wild, a sprawling, imaginative ecological fable about embattled people living in the fast-disappearing Louisiana wetlands. In a mostly positive review, I wrote, “Zeitlin’s film seeks to celebrate Cajun resilience. Even as it sometimes lurches from one scene of heightened emotion to another, it delivers a vision of a culture that isn’t easy to shake … [T]he film plants us in its vivid, handmade world and mostly keeps us there.”

However, in the course of discussing aspects of the film’s scientific reliability, I expressed doubts about the film’s presentation of the region’s levee system and how characters rectify the problems it creates. As it happens, I might have consulted Barry Yeoman, a former staff writer for the Independent and a prolific writer for publications ranging from The American Prospect to Audubon magazine. Over the years, he’s covered ecological issues in the Gulf Coast extensively, writing an 11-part series about land loss in Louisiana for OnEarth magazine’s online edition, as well as producing radio segments on the issue for Louisiana Public Broadcasting. After reading my review, he sent us the following note:

“I agree with you about the many strengths of the film … I liked it a lot, despite the flaws. But I wanted to discuss one factual point about your review:

[I]n the engineering cosmology of this film, the saltwater flooding of the Bathtub is the fault of a levee that is designed to keep the nearby New Orleans-like city dry. Puzzlingly, the Bathtub denizens reason that if the levee could be breached with dynamite they somehow have in their possession, the ocean of salt water will recede and life will be restored.

“This is actually reasonably true. The levees that run all the way down the Mississippi, past New Orleans, are the main culprit in the 25 square miles of land loss that Louisiana suffers every year. The marshy soil at the bottom of the delta’s wetlands naturally subsides, and until the early 20th century was kept at a constant level by the sediment that washed over the Mississippi’s banks during flood stage. Every year, the delta would sink a bit, only to be replenished by silty water. This dynamic process worked well until 1927, when leveeing began in earnestand then the land loss began. It’s been accelerating ever since, for a variety of reasons, including the 10,000 miles of canals dug by the oil-and-gas industry for navigation and extraction. (The canals have also sucked saltwater inland.)

“Not everyone lives inside the levee system. In particular, Isle de Jean Charlesthe real-life setting of The Bathtub, where the film’s protagonists livehas undergone catastrophic loss. The island used to be four miles wide; now it’s about 1,000 feet wide. And this is precisely because engineers want to keep New Orleans, Houma (the nearest city) and other large communities dry. South Louisiana is a land of hydrological haves and have-nots.

“There have been numerous proposals for stemming land loss and addressing the saltwater-freshwater balance. The ones that hold the most credibility among coastal scientists involve selective breaches in the levees, which would allow sediment overwash to begin anew and to restore the historic salt balance.

“Admittedly, such breaches would not play out like the scene in Beasts. Still, I’m concerned about the review’s possibly leaving the impression that economic sacrifice zones like The Bathtub don’t exist as a result of the levees. This is a life-and-death struggle every day in Louisiana.”

Beasts of the Southern Wild continues its ongoing engagement in area theaters this weekend.