GRAND ISLE, La. – Not all jewels shine deep-green like emeralds or have the sparkle of diamonds. Some tumble from algae-coated cages in a rush of rock and shell, briny water splashing alongside them onto the boat deck.
These fine commodities are oysters, grown and harvested just off Louisiana’s coastline. Traditionally, they’ve been farmed on seafloor beds, but some producers are now cultivating oysters in a string of floating cages. Grand Isle Jewels, the umbrella brand for all off-bottom oysters in Louisiana’s barrier island community of Grand Isle, Louisiana, are marketed as precious gems of the Gulf Coast.
“You create this craze for a certain item, and everybody's jumping on it,” said Kirk Curole, owner of Bayside Oysters in Grand Isle.
After retiring from a career in oil and gas, Curole began harvesting off-bottom oysters as a hobby that turned into a small business. He now spends his days on the water, clad in rubber waders and toughened rubber gloves as he pulls his crop from the floating cages.
“It's the ‘bougie’ oyster. It's the boutique oyster,” he said. “Everybody wants to try it.”
But Louisiana is exploring off-bottom harvesting as more than just a marketing strategy. In its final environmental impact statement for the controversial Mid-Barataria Sediment Diversion project, the U.S. Army Corps of Engineers lists the state’s strong interest in off-bottom oyster cultivation as a way to help build resiliency into an industry under threat from sediment diversions.
Whether this technique can beat back worsening hurricanes, climate change and the impact of sediment diversions is still undetermined.
An industry at risk
On-bottom culture, where oysters attach to reefs or substrate on the water’s bottom, is and has been the most popular method of oyster harvesting in Louisiana’s waters, fed for centuries by the wealth of nutrients carried down the Mississippi River from its entire basin and into the delta region.
“[Louisiana] oysters are probably in the best location in this regard because they show very high growth,” said Romain Lavaud, an oyster scientist and researcher at Louisiana State University. “They can be harvested within a year, whereas in other parts of their distribution range it can take two to three years.”
But Louisiana’s environment can also be an oyster harvester’s worst enemy. Hurricanes inflict huge damage to oyster reefs, and heavy rains can dilute the salt content of the water, killing oyster crops.
“You're kind of also, like in any agriculture production, at the mercy of environmental conditions,” Lavaud said.
Farming oysters has always been a gamble, said Peter Vujnovich, a third-generation on-bottom harvester based in Port Sulphur, Louisiana. Oyster farmers can lose big after a storm, he said.
“Mostly you try to protect your house, your boats and the equipment and stuff like that, and the rest is really up to God,” Vujnovich said. “Make the sign of the cross … just hope you don't get a direct hit.”
Port Sulphur saw large losses to its oyster reefs in 2005 from Hurricane Katrina, which eliminated seeding ground for traditional farmers.
Then, there are sediment diversions, a coastal restoration approach that mimics the natural process of building a delta with silty water from the Mississippi River. There are multiple planned diversions in Louisiana’s Coastal Master Plan to rebuild wetlands that have been diminished through hurricanes, natural subsidence and countless man-made canals.
The Mid-Barataria Sediment Diversion project is the most expensive and one of the more controversial projects because of its likelihood of “major, permanent, adverse impacts” to oyster populations, according to the U.S. Army Corps of Engineers environmental impact statement.
It would alter or eliminate vast swaths of oyster habitat in the Barataria basin along the toe of Louisiana’s boot, with the goal of returning the area to what it looked like before the effects of sea level rise, erosion and subsidence changed it. Replacement oyster grounds could appear in other parts of the basin, the report suggests, but their location would have to be evaluated in the future.
On-bottom harvesters need the reefs the diversions would likely eliminate. Gov. Jeff Landry issued a 90-day pause on development for the nearly $3 billion project that went into effect April 5, citing in part its impact on the oyster industry. The project has been all but cancelled in its original form, with politicians like Louisiana Coastal Protection and Restoration Authority chairman Gordon Dove suggesting smaller diversions take its place.
Seeding off-bottom solutions
Off-bottom oyster harvesting isn’t new globally; in fact, the technique has had a lot of success in areas like the Virginia coast. But it’s relatively new to the Gulf Coast, where growing on-bottom has been productive, particularly in Louisiana.
The impending diversion projects are expected to change that.
The Corps of Engineers has identified off-bottom oyster cultivation as a potential way for the industry to adapt to the threats posed by sediment diversions like changes in salinity and the burial of reefs. The federal agency has oversight of all Louisiana coastal restoration projects and acts as a gatekeeper for what’s proposed in Louisiana’s Coastal Master Plan.
Off-bottom harvesting can help with protection against predators, like red drum fish and stone crabs that eat oysters on the bottom, and offer a way to harvest in areas without abundant reefs, left stripped after storms. But the key advantage the Army Corps and the state’s Coastal Restoration and Protection Authority cites centers around mobility.
Floating cages could, in theory, be moved in response to a low salinity event such as the opening of a diversion. But harvesters need permission from regulators to store their gear and oysters in different bodies of water from where they’re harvested, and that can take up to 18 months to obtain. Also, neither the Louisiana Department of Health nor the U.S. Food and Drug Administration allows oysters to be out of the water for more than 24 hours.
Mobility could also help mitigate hurricane damage even if the oysters have to be jettisoned so the cages could be moved on shore temporarily during a storm.
Curole said even if he loses his crop, it’s worth it to save his expensive equipment and harvest off-bottom again after the storm.
“If a storm is coming, I'm just going to go pick up my equipment, even if I have to dump my oysters out,” he said. “I can oyster next year, or I can oyster in two or three months.”
This works for Curole, whose trailer can haul up to 350 oyster cages, but his business is relatively small. To achieve consistent profitability, a producer would have to have thousands more cages, one analysis found, and there might not be enough time to relocate all the cages they would use. The loss could spell doom for a business’ bottom line.
“It has not been demonstrated that gear can be sunk and retrieved cost-effectively or relocated in time to avoid damage and loss of both gear and crop,” Daniel Petrolia, a University of Mississippi agro-ecomomics professor, wrote in a 2023 report on the economic challenges to off-bottom harvesting in Louisiana.
Time is in short supply as hurricanes approach, especially with storms developing and intensifying more rapidly in recent years. Off-bottom oyster operations are already expensive compared to traditional harvesting, according to the Petrolia report. He concludes the loss of harvesting gear to a storm could sink an off-bottom oyster harvester’s livelihood indefinitely.
Reliant on subsidies
Petrolia’s report found that the financial success of off-bottom oysters in Louisiana relies entirely on state subsidies.
Off-bottom oysters from the Gulf excluding Louisiana grew from zero to 12% of all the off-bottom oysters produced in the Southeastern United States from 2013 to 2018, according to another study looking at the technique’s reception in the Gulf. Louisiana began to offer grants for off-bottom harvesters in 2022 to try and promote the expansion of the technique, starting with $3 million in total to address the high startup costs.
“Although the … grant program can indeed provide a hand up to existing growers, it does distort market signals and may give the impression that economic conditions are better than they actually are,” the Petrolia report reads. “The eventual disappearance of the [subsidy] program will likely have consequences.”
The report also doesn’t expect “the average small-scale operation” to be profitable, even with funding support from the state. Curole did not receive a grant from the state and said his business is currently profitable, but he represents a smaller set of growers that operate more for supplemental income on small acreage, harvesting anywhere from 20,000 to 120,000 oysters throughout the seasons.
True profitability becomes more possible, according to the report, with larger businesses starting at around 4 acres expecting to harvest up to 960,000 oysters from those acres.
Off-bottom cultivation was never pitched as a silver bullet solution for the oyster industry’s future. Louisiana SeaGrant, a National Oceanic and Atmospheric Administration-Louisiana State University partnership, is responsible for the majority of the off-bottom funding and hatchery support. It commissioned Petrolia’s report and stands by the idea that off-bottom culture is meant to supplement the industry when traditional methods face challenges like reef loss.
Different off-bottom initiatives continue to support the oyster industry, such as the expansion of hatchery operations that farmers rely on for seed. Further research, such as how to sink and secure cages during hurricanes— and grant money to support it— are also needed.
To harvesters like Vujnovich, the survival of the industry doesn’t hinge on a choice between off-bottom or on-bottom cultivation. It’s whether or not these tools will help his industry stand on its own again.
“They'll always have a few hardcore like me,” he said. “The question is not if it'll survive; it's if it'll flourish again.”
This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouri in partnership with Report for America, with major funding from the Walton Family Foundation.