Alabama's Oyster Restoration Efforts Continue with Additional Help

Newton said the oyster catchers and environmental organizations recognized that decline and stepped up to help.

"There have been grassroots efforts over the past couple of years," he said. "They've taken it upon themselves to do whatever they can to provide somewhat of a quick relief and provide some benefits to the oyster population."

Those methods traditionally include cultch planting projects, according to Newton. Cultch is a hard substrate made of a variety of materials, mainly limestone rocks, oyster shells and mussel shells. That material is then deployed in areas with the best environmental conditions to help larval oysters, called spat, find a place to attach and then grow into harvestable oysters.

"After you add that substrate to the water, you rely on natural processes to result in the settlement of larval oysters, and then those grow into mature oysters to have the oyster population that everybody wants," Newton said.

One of the larger projects that included cultch material was done by the AWF Oyster Restoration Initiative a month ago. Limestone rock was hauled from the Tuscumbia area to the Tombigbee River, where it was loaded on barges to make the length-of-the-state journey to the Dauphin Island area. About 4,600 tons of washed limestone were then placed near Cedar Point.

"In the past few years, AWF has done an excellent job of coordinating with MRD biologists to identify water bottoms for enhancement that are most likely to benefit oyster populations," Newton said. "They planted No. 4 limestone, which was selected because of its long-term durability. Oyster shells generally last about five years before they break down. Limestone lasts upwards of 10 years. The idea is that this long-term, durable material will provide quality settlement substrate and hopefully the environmental conditions are suitable during that time period to result in some type of generational survivorship of the oysters."

Life can be difficult for oysters in habitat like the Alabama Gulf Coast. If the water is too fresh, the oysters slowly die. If there is too much salinity, a snail known as the oyster drill will attack the oysters and kill them. To deal with the oysters' fragility, the deployment of cultch material is one method to try to offset that. Sometimes it works, and sometimes it doesn't.

"In 2023, AWF planted No. 4 limestone in 77 acres in the Cedar Point Beach area," Newton said. "We saw some short-term success with the settlement of larvae on that Cedar Point Beach plant. Upwards of 6 million larvae were in that 77 acres. However, those larvae essentially died the following year due to freshwater, drills and possibly other stresses from the environmental conditions that are fighting against our oyster population. The good news is the reef material is still there and can grow new oysters this year if the conditions are right."

"This year, AWF planted another 50 acres in the Cedar Point West area. We're hoping we see the short-term success of the Cedar Point Beach area, and we're also hoping we see long-term stability in the survivorship."

Newton said the sites of the deployment of the cultch material by the AWF were chosen for specific reasons.

"They were selected because they were adjacent to our most productive, most stable oyster reefs," he said. "They are also somewhat shielded from the water that comes out of the Mobile River. When you get a freshet (sudden influx) from large amounts of rain in the watershed, it reduces the salinity in the bay to a level that oysters can't tolerate. Another reason that site was chosen was it has stable dissolved oxygen, and it's in the historical footprint of our most productive reefs."

MRD Director Kevin Anson addressed the oyster catchers' contribution to the restoration efforts.

"We have a group of seasoned oyster catchers who have been catching oysters nearly their entire lives," Anson said. "They have seen this transition from really good catches of oysters back in the 90s, and they've seen in recent years the dramatic decline in the populations of oysters. So, they took it upon themselves to volunteer their time to deploy oyster shell that they have sourced from seafood dealers. They wanted to put something back, literally, back into the system and their industry."

MRD issued special permits that allowed the oyster catchers to deploy oyster shells as well as sample oysters by catching them with tongs.

"They sampled them and then had to return them to the water," Anson said. "It was a good faith exercise to allow them to take a look at different areas and help hone down the locations that would provide the best benefits. They also provided us with some additional ideas and thoughts about what they thought the best locations would be.

"Heron Bay is the longest term productive oyster area in the state, even during these more dynamic environmental times. There were also a couple of areas in Dauphin Island Bay. We're looking for areas where oysters can maintain when salinity drops. Those areas would allow them to live multiple years and be able to reproduce and get more recruitment, more baby oysters into the system, and increase the footprint of oyster habitat."

Newton said the oyster restoration is moving in new directions to try to increase the chances of success, including planting live oysters by AWF. The first planting with small oysters saw limited success. The next effort used larger 2-inch oysters with the hopes of better survival.

"It's important to keep working on these novel approaches," Newton said. "Traditional methods aren't working like they used to when we could just plant the bottom with oyster shells anywhere on the reef. I'm proud of these other groups executing these projects. We have to think outside the box and find alternative methods to affect positive change on oyster restoration efforts. The NRDA oyster project and partnering with AWF and the oyster catchers will do just that."

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