After sharp declines, legislators, private groups work to rebuild Alabama oyster population

By Allison Marlow
Managing Editor
Posted 3/3/23

The Alabama Marine Resources office on Dauphin Island sits on what is essentially an ancient trash heap – a mound of discarded oyster shells.The hollowed-out animal homes were placed there …

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After sharp declines, legislators, private groups work to rebuild Alabama oyster population


The Alabama Marine Resources office on Dauphin Island sits on what is essentially an ancient trash heap – a mound of discarded oyster shells.

The hollowed-out animal homes were placed there hundreds if not thousands of years ago, by Native Americans who had harvested them for their own meals.

The discarded shells were tossed haphazardly into a pile and have been there ever since.

Oysters have always thrived on the Gulf Coast. Until the last century, that is.

Development and an onslaught of natural disasters in the Mobile Bay area changed things. Everything, in fact.

Scott Bannon, director of Alabama Marine Resources, said as industry grew, and the population with it, the buildup on land impacted the water and with it, the oysters.

Construction of the Mobile Causeway, Theodore Industrial Canal and Gaillard Island, a man-made island in Mobile Bay, changed the way the water flowed.

Commercial development along the shoreline impacted the water too.

Runoff that makes its way to any river system between the Gulf of Mexico and Tennessee eventually flows into Mobile Bay impacting the oysters and all the life teaming in the estuary there.

And in 2004 and 2005 back-to-back hurricanes Ivan and Katrina caused havoc.

Hurricane Katrina cut Dauphin Island in half, increasing the salinity levels in the water, meaning the oysters' predators could thrive and eat their way through the population.

Several years of drought conditions also meant less fresh water flowed down the river system and into Mobile Bay, again increasing the salinity levels. And again, the oysters' No. 1 enemy, the oyster drill snail, a saltwater snail that eats oysters, arrived. Hungry.

"There are things that have happened over history that have changed what we're seeing for these public oyster reefs," Bannon said.

In 2018, Alabama didn't even have an oyster season. The year before, the harvest was open for just six days.

"Those were tough years," Bannon said. "This has been a way of life for people for multiple generations. The system kind of has to rebound on its own and there were a lot of naturally occurring challenges. But we were really looking at what we could do to help enhance this."

And consumers hungry for oysters wasn't the only reason there was cause for alarm. Oysters help Alabama's waters thrive.

"Oysters are a foundational critter in our watershed. We have to have them in order to have a healthy waterway," Bannon said. "They are a food source for lots of different marine species that swim in our waters and they are a very valuable part of the eco system.

"We need to have them whether we are harvesting them or not."


As oysters began to disappear, worse, there was no system in place to help monitor and guide their return.

In 2013, the Alabama legislature created a seven-member Shellfish Aquaculture Review Board tasked with developing policies and a program for building and regulating commercial oyster farming.

The efforts resulted in the Alabama Department of Conservation and Natural Resources (DCNR) proposing a new shellfish aquaculture rule in 2014 which provided easements of state-owned submerged lands to encourage off-bottom oyster harvesting.

Leaders say the move reduced out-of-pocket expenses for commercial harvesters, eliminated confusion and led to the development of several commercial oyster farms and increased oyster production in Alabama.

There are now several commercial oyster farms in Mobile and Baldwin County. Many, like Murder Point Oysters, began in the oyster aquaculture park established and run by Auburn University. Aquaculture sites (farms) provide a year-round cultivated product that is highly sought after, primarily in the half shell market.

Perhaps, most importantly, it also established a system of accountability, giving officials the ability to monitor and close separate pieces of the oyster reef to fishermen, which is laid out in a grid system.

Monitoring smaller sections of the reef, Bannon said, has equaled larger output.

Alabama is currently the only state that manages its oyster beds with such a laser focus. The grids are 500 square meters each and are assigned a letter and number code. Using the Outdoor Alabama web page, harvesters can see which grids they are in, and which ones are closed.

"If we only open and close large-scale areas it limits the opportunities for harvesters to work," Bannon said. "When we open and close small areas we keep people working."

Enhancing and growing those existing reefs, in many places meant simply kickstarting populations that had been dormant, Bannon said.

It starts with an itty-bitty spat, the officials name for a baby oyster. For all the havoc oysters have faced, none is more susceptible to change than the spat.

The spats float along happily as most kids do until they find substrate – a rock, shell, pier piling – something to attach to and that is where they grow.

But like human toddlers, they can be picky. Too wet of a spring? Nope. Water too salty? No way. The water conditions have to be just right.

"It's a difficult balance nature has to provide for there to be a sustainable oyster harvest," Bannon said.

To make Alabama's waters as oyster friendly as possible, agents in the marine resources office constantly survey and monitors the oyster reefs.

In places where oxygen levels are low mounds are built to raise the oyster beds higher. The manmade homes do double duty as a protected space the spat can attach to and avoid predators.

Officials also plant used oyster shells as substrate for the spat to grow on. MRD staff also limit the size of the oysters and the number that can be harvested. Alabama only allows those 3 inches in diameter and larger to leave the water.

Bigger oysters produce more spat, meaning a larger harvest in years to come.
All of the efforts to rebuild the oyster population have led to a positive return in Alabama oysters.

Last year monitors found lots of small oysters clinging to their substrate and thriving. When the season opened in October, many had expanded and grown to harvestable size.

"That's a good sign," Bannon said, "and we hope to continue to see positive growth every year."