It is impossible to picture Louisiana without oysters. They play prominent roles in our food, art, and culture. They are a way of life and a livelihood for those who earn a living harvesting them. They help filter and clean our waterways. They are so ingrained in our state that they even make up part of the very ground on which we are all standing.
Yet despite their importance, and despite the role they play in our state, they are under threat. The oyster as a species has done its best to keep up with ever-evolving environmental conditions, but those conditions seem to be changing too fast for the oyster to keep up. This places not only the oyster at risk, but the people who rely on them to make a living, and the way of life that generations of oyster harvesters have enjoyed.
Oysters: The Family Business
In 2013 Boris Guerrero and his father decided to get a lease in Grand Isle, the goal being to try their hand at farming oysters. Farming was not necessarily new to them; they had been sugar cane farmers. So, relying on nature to produce a living was not new, even if there was a steep learning curve going from land to water.
“We liked farming, and we thought this could be like land farming,” said Boris.
They wanted a chance to continue farming with as little environmental impact, which led them to the oyster.
“You don’t need to feed them, you don’t need to fertilize them, you don’t need to put any chemicals on them. Let the water flow through them, and they grow. So, I think that’s the beauty in oysters,” Boris said.
Oysters are natural filter feeders, which means that by pumping water through their gills they collect particles of food or other nutrients they need to grow. It is not just food that they collect, however, sediments and other particles that are suspended in the water get collected, and in turn, this helps keep water clear and clean.
“In an oyster reef you can have a huge habitat. Shrimp, crabs, fish, so it’s very important ecologically speaking,” said Carolina Borque, an oyster expert for Louisiana Fish and Wildlife.
Attracted to both the importance of oysters to an ecosystem, and the fact that they are a useful source of protein, Boris founded Grand Isle Sea Farms.
Old Industry, New Ways
The oyster industry has been around since the early 1800s in Louisiana, and since then it has grown into a major money maker. In the 200 years since the early days of commercial oysteries the industry has become responsible for almost 4000 jobs and has an economic impact of more than $300 million.
Producing almost 70 percent of the country's oysters, the Gulf of Mexico is one of the most important resources for the precious species, and Louisiana sits right in the middle of it. These days almost 98 percent of all harvested oysters come from private leases, as those in the industry have moved to growing oysters themselves.
Yet for an industry that is worth so much, oysters can be notoriously fickle. Minor changes in temperature and salinity can cause oysters to die off, and since they take on the properties of the water they are growing in they can be very susceptible to pollution. Unlike shrimp or fish, oysters cannot simply move to areas that are more favorable. So, a particularly rainy year can leave oysters vulnerable to an influx of fresh water, or an abnormally hot summer could cause water temperatures to get too high.
To help give growers a little more control over where their oysters are growing, Boris and his father practice a relatively new method known as “off bottom farming.” Instead of anchoring on an attached bed, the oysters are grown in floating cages that are anchored to the bottom. This helps protect them from low tides and keeps them in an environment favorable for growing. In the event of a storm or a major influx of freshwater it also gives the farmer a chance to move them to a more favorable location. When much is up to the whims of nature, any control a farmer can have is certainly appreciated - although that control will only go so far.
"That Was a Bad Day": Hurricane's Impact on the Industry
On October 28, 2020, Hurricane Zeta made landfall near Grand Isle with winds around 115 mph and gusts that were even higher. It was the third hurricane to strike the Louisiana coast that year, and the second major one. It came ashore along the same stretch of water where Boris had set up his oysters, ripping up the anchors he had placed, scattering cages across the bay, and killing whatever he had growing.
“That was a really bad day. Basically, all the work that we put in for seven years disappeared. The spot where we had the farm was just water, there was no oyster gear, or anything left. We basically had to go around the bay and find our gear. We found some of it, very little, Boris said, reminiscing on the days after the storm had cleared. He was not the only farmer who had faced the storm, and it was certainly not the first time a hurricane had wiped out a crop of oysters.
The damage caused by hurricanes goes beyond simply a lost crop, the violent nature of hurricanes is powerful enough to change the landscape that new oysters require to grow. Eroding the coast and covering oyster beds in mud, hurricanes have the power to reduce areas where oysters can grow.
"You do have a lot of issues of sedimentation in Louisiana, our coast is eroding so that is part one. We have huge hurricanes and storms every year so that doesn't help either," said Carolina Bourque. And this shrinking of habitat, by both hurricanes and people, has scientists worried about the future of oysters in the Gulf of Mexico.
A Population in Decline
"Since the early 2000s we have seen a decline in the oyster population, especially in the public seeding grounds," Carolina said, pointing out that fall in oyster population along the public grounds has been exponential. While the dip in population is obvious, the reason behind the drop is not as clear. The research by the Louisiana Fish and Wildlife is on the public seed grounds, but Carolina pointed out that the private leases would be facing similar environmental conditions. And the issue that she had found was a lack of spat, or baby oysters.
"We never had issues before there would be baby larvae all over, they would rebound very fast. And since the 2000s there's a lack," she said. The reason behind the lack is spat is unclear, but one of the beliefs is that there is not enough suitable material for the spat to latch onto. "You can have larvae in the water column but if they don't have a perfect spot to sit on it, they just won't make it to reproductive size,” she explains.
Louisiana Wildlife and Fishing is currently working on projects to get more substrate into the water to encourage the growth of oysters, by sinking limestone in areas where oysters could grow.
The lack of spat is a major concern because without a younger generation of oysters ready to grow it makes it harder for populations to bounce back after mortality events. These events, such as hurricanes, that can kill off a population can have an outsized influence on the total number of oysters without baby ones to replace them, something that Fish and Wildlife has already noticed.
“It's mortality after mortality. You know Mother Nature is not rebounding like she used to,” she adds.
This kind of decline can be deceptive, making populations look relatively stable for extended periods of time. Some researchers along the Gulf Coast believe, however, that while a population may appear stable it can suddenly collapse and crash down to nothing. This means that it may not be one singular factor that is threatening the Gulf of Mexico’s oysters but a multitude of little ones - each one taking a toll and leaving populations even more vulnerable to extreme events.
The Flood of 2019
In 2019 the oyster of the Gulf Coast experienced one of those extreme events. A deluge of heavy rain across the country’s heartland ended in one of the most intense flood seasons on record. The Mississippi River ran swollen for months forcing the Army Corps of Engineers to open the Bonne Carre spillway in February. It was left open until April, sending all that fresh water down into south Louisiana’s saltwater basins. As the river remained swollen, the Bonnet Carre was opened again - the first time it had ever been opened twice in one year - and it remained open again from May into July. It wasn’t just the Mississippi River that was running high, the Sabine and Atchafalaya were both full of fresh water that was emptying into the Gulf of Mexico.
For the oysters, this was nothing short of catastrophic.
"2019 was extreme, it affected every basin in Louisiana. It caused mortality from the side of Texas to the border of Mississippi, including the state of Mississippi. Some areas had mortality of 80 to 100%," said Carolina.
The event almost broke the industry, which already is balanced on the fickle nature of oysters.
Populations were down across the board and the industry suffered one of the largest die offs of oysters in the Gulf Coast. Fisherman say that the harvest has started to rebound but Hurricane Ida coming ashore in August has made for another tough hurricane season for Louisiana. The conditions for oysters may only get worse as experts say that a changing climate will have the ability to produce more seasons such as the one we experienced in 2019, along with warming ocean temperatures and stronger storms. Oysters may be in trouble.
A Hopeful Harvest in the Spring
It had been five months since I spoke with Boris and his father about recovering from Hurricane Zeta when Louisiana was struck by another storm. Hurricane Ida came ashore in Grand Isle, wiping out all their remaining equipment. Grand Isle Sea Farms had lost everything - from their cages to the boat that took them out to harvest.
Since that storm they have still not been able to raise an oyster, but they hope to start another harvest again in the spring.
