Alabama's Oyster Restoration Efforts Continue with Additional Help

By DAVID RAINER, Alabama Department of Conservation and Natural Resources

The Alabama Department of Conservation and Natural Resources (ADCNR) was recently awarded $7.1 million in Natural Resource Damage Assessment (NRDA) funds for the project: Improving Resilience for Oysters by Linking Brood Reefs and Sink Reefs. The project aims to increase oyster abundance and restore resilience to oyster populations by increasing reef connectivity through larval transport and the construction of oyster reefs over a range of habitats and salinities. The project will create a network of high-vertical-relief brood (protected) reefs that link to existing and/or created sink (harvested and/or protected) reefs through larval transport, as well as increase oyster population sustainability and oyster reef resilience.

ADCNR Commissioner Chris Blankenship serves as the lead Trustee for Alabama on the NRDA Trustee Council that oversees project selection and implementation for these DWH Oil Spill Funding components.    

ADCNR’s Marine Resources Division and Deepwater Horizon Restoration Section are working with the University of South Alabama and Auburn University to identify restoration sites and techniques that are most likely to yield best results for the project.  Building on the Marine Resources Division’s practical working knowledge and management of the fishery, ADCNR’s goals for this stage of the project are to understand biological, physical, and chemical factors that impact restoration success and use that information to build and enhance certain oyster reefs.  This project is expected to take about two years.

To help with oyster restoration in the short term, ADCNR’s Marine Resources Division (MRD) is teaming up with local oyster catchers and the Alabama Wildlife Federation (AWF) to try to bolster the current oyster habitat along the Alabama coast.

Craig Newton, MRD District Supervising Biologist, said that two grassroots efforts are underway to try to revive the state’s oyster reefs.

“Since the 2000s, our oysters have been primarily restricted to one main area,” Newton said. “Historically, our oysters have been anywhere from Whitehouse reef off Alabama Port south to the Cutoff at Jemison’s (Bait Shop across from Heron Bay), with Buoy reef, Cedar Point, Heron Bay and Portersville Bay as areas of significant harvest. All these places had oysters.

“For the last 15-20 years, we’ve been mostly restricted to Heron Bay and Cedar Point.”

AWF Executive Director Tim Gothard said the 50-acre AWF Cedar Point West Oyster Cultch Planting represents continuation of a great partnership between AWF, ADCNR Marine Resources Division, Vulcan Materials Company, and Cooper Marine.

“This is our second large-scale cultch planting project in the Cedar Point area,” Gothard said. “Those projects would not take place without these key partners. AWF is committed to the Coastal Alabama Comprehensive Oyster Restoration Strategy, developed by ADCNR Marine Resources Division in conjunction with NOAA. On-the-ground and on-the-water conservation work is just part of AWF’s DNA and we value the opportunity to make projects like this a reality.

“The 4,600 tons of limestone rock oyster cultch provides a significant window of opportunity, up to a decade or more, for the right conditions to come together for oyster larvae to attach and successfully develop. AWF chose to do this project within MRD’s Oyster Management Grid System. Ultimate success over time would be oysters of multiple age classes established on the site, including oysters of commercial harvest size, and the ability for a portion of those oysters to be harvested and utilized for food, per MRD oyster harvest rules and regulations.”

Alabama’s harvest last season, which typically starts in October, resulted in 5,153 sacks, or 210,000 meat pounds, of oysters taken from state waters. That compares to the most recent peak of 1.2 million meat pounds taken in 1992.

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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