Coastal scientist, Louisiana Universities Marine Consortium
During the Covid-19 lockdown, while others baked sourdough bread, Alex Kolker was studying satellite images of the Mississippi River Delta. As an oceanographer, geologist, and climate scientist, he is interested in how the Louisiana coastline loses land, and also how it builds that land back.
As he examined the images, Alex noticed a channel connecting the Mississippi River to Breton Sound and Quarantine Bay. Over the course of about a year, he says, the tiny cut had widened into a veritable river. Neptune Pass, as it’s called, carried more than four times as much water as New York’s Hudson River.
That water contained sediment, which was building land. Alex started noticing islands forming in Quarantine Bay. This rapid land-building process was the opposite of what’s happening in much of Louisiana, which has lost 2,000 square miles in the past century.
Coastal scientist, Louisiana Universities Marine Consortium
One reason for this land loss is that humans have disconnected the river from the wetlands by building levees for flood protection. “For many years, a lot of people in the scientific, environmental, and eventually the government community have been focusing on the idea of restoring the landscape by partially diverting the flow of the Mississippi River,” Alex says. “The river was not flowing through its wetlands anymore, and one of the ideas of rebuilding the landscape was to partially divert the flow of the Mississippi River in order to restart this natural land-building process.” Neptune Pass was a natural experiment that, to Alex, showed how sediment diversions can work.
A $3 billion sediment diversion project had been on the books in Louisiana. A week before our interview, the state government canceled the controversial project.
After the interview, we climbed into a boat piloted by Captain Richie Blink and headed toward Neptune Pass. Striped mullet leapt out of the water and feral cattle wandered along the banks. Birdlife surrounded us: roseate spoonbills, black-neck stilts, yellow-crowned night herons, snowy ibis. In Quarantine Bay, we jumped out of the boat to stand on newly created land covered by ankle-deep water. A sprig of giant cutgrass poked out from the bay: the first evidence, Kolker said, of naturally occurring vegetation.
“This is one of the places that makes me feel hopeful that nature can heal some of humanity’s mistakes really quickly,” Blink said from the boat. “If we just let it.”
On how Louisiana offers lessons to the world:
“Katrina was a really big storm. But at the end of the day, the damage in New Orleans was an infrastructure failure. And it was a colossal failure on many levels. Obviously, the levees were not built to a high enough standard and not maintained to the standard that they were even built.
“And then there were other things that surrounded that as well, including very significant wetland loss across the Louisiana coast, and particularly in the areas around New Orleans. That allowed storm surges to propagate further inland and do more damage.
“Wetlands provide a buffer system against floods. And 100, 150 years ago, New Orleans had dozens of miles—maybe even in some directions over 100 miles—of wetlands that protected it from the sea. New Orleans was something of an inland port 150 years ago. The landscape would have been surrounded by cypress swamps. It would have been surrounded by wetlands and marshes. There would have been some natural areas of high ground.
“For 15-plus years, I’ve been looking at the geology of this landscape in a variety of different ways. Why do we lose land? How do we rebuild land? And then more broadly, in the more recent terms, what lessons does Louisiana have for the rest of the world about how we’re going to deal with a future of climate change and sea-level rise?
“Longterm, people need to understand this, because nearly half the world population lives by the coast. New York and Houston are coastal cities. Lagos, Nigeria is a coastal city. London, England is a coastal city. Tokyo is near the coast. There are coastal population centers across the world. One of the things that keeps me going is to know that there are people all across the world that need to understand the coast and how it is changing for their long-term survivability and sustainability.
“Because Louisiana has been on the front lines of coastal change, the lessons that we have learned here in Louisiana are valuable to people across the world. And so one of the things that keeps me going is this idea that I can help people beyond here understand what to do to restore and maintain their coasts.”
“As a researcher my job is to look at the information and communicate it. The data says that a lot of people are beginning to leave the lower parts of Louisiana. Plaquemines Parish as well as many other southern parishes have lost roughly 5 percent of their population just since 2020.”
On navigating competing interests:
“One thing that has happened is that the Army Corps is scaling back the flow of Neptune Pass.
“Many of us want to see land built in Louisiana. But another thing that can happen when rivers create new channels is you can create dangerous currents, and you could get sandbars to form in the main stem of the Mississippi River, which could be hazard to navigation. And so you’ve got this balance in a channel.
“This is a big river and there are absolutely multiple benefits, multiple interests, many parties involved, many organizations. And in addition to all of the human interests that are large, the river itself is really large. The river itself carries a lot of water, and if it was mismanaged, it could be very dangerous.
“I could probably say all of us would prefer a state with more land than less land. And no one wants to see a barge laden with chemicals run aground. Actually, why we do science is to help people understand this system so we can get that balance right. But it’s a hard balance to get right.”
From John:
I’d been out on this stretch of water before with Riche Blink. In 2021 I interviewed him for Lessons on the Road to Peace and spent a day exploring the southern end of the Mississippi and its backwaters with him. So when we needed a boat captain to take us out to Neptune Pass with Alex, I called Richie. In a small-world moment that I should have expected, of course, they knew one another.
We shared the river channel with freighters hauling international cargo and pushing bow waves in front of them. We motored past feral cattle and alligators. We passed abandoned oil infrastructure and pulled soil samples from recently deposited sediment.
Eventually, we stepped out of the boat into shallow water, onto barely submerged land that was not there half a decade ago.
We did the portrait of Alex in Quarantine Bay, standing on new delta sediment just below the surface. We stepped out into the shallow water. Richie dropped anchor and held the boat in position. Barry kept the light steady in the breeze. and the interns shot a little behind-the-scenes footage.
To read the introduction to this series, follow this link.
Still Here: Stories from a fragile coast
To listen to our podcast, follow this link or find us on the platform of your choice.
A Peace of My Mind on Buzzsprout
Credits:
Interview and text: Barry Yeoman
Photos: John Noltner
Editing and production: summer interns Kate West, Sawyer Garrison, and Kaitlin Imai
Audio engineering: Razik Saifullah