Research on Inshore Species Yields Interesting Revelations

By DAVID RAINER, Alabama Department of Conservation and Natural Resources

Research into numerous saltwater fish species has produced some interesting revelations, including how important the Mobile-Tensaw Delta is to the recruitment of those species, which include southern flounder, spotted seatrout (speckled trout), red drum (redfish) and tripletail.

Dr. Sean Powers, Director of the Stokes School of Marine and Environmental Sciences at the University of South Alabama (USA), said the research team and recruited anglers have been tagging the inshore species with regular tags and acoustic tags that are used to track movement. The acoustic tags are picked up through the network of hydrophone arrays deployed throughout Gulf coastal waters.

The flounder research has been funded by the Alabama Department of Conservation and Natural Resources (ADCNR) for the past five years and is producing results that weren’t exactly expected.

“We’re still looking at when flounder are moving offshore and what is causing changes in that,” Powers said. “The main thing with flounder is the growing evidence with our tracking and other research that indicate there’s a decent amount of that population that goes offshore and stays offshore. Spearfishermen have told us about that for a while. Now we have proof when we analyze the chemical signature of the otolith (ear bone) that some flounder are staying offshore.

“We refer to that as cryptic biomass – the biomass we think can produce new eggs and new recruits that are really not harvested because they stay offshore. That might explain why flounder populations were so low, and yet we still had enough to produce good recruitment years. The last few years have been really good for flounder. In the stock assessment we do for ADCNR, we’re still not showing those fish are joining the older population yet. We know we’ve had several good recruitment years, so the question is, if the population is so low, where are all those eggs coming from? The spearfishermen have been saying the flounder are on the low relief-type structure, like bridge rubble, so we’re going to look at that in the next year.”

Powers said another chapter in the flounder story involves the vast Mobile-Tensaw Delta, which covers more than 200,000 acres just north of Mobile Bay, including more than 20,000 acres of water. 

“The variability – when we have good years and when we have bad years – seems to be a function of how much grass in the Delta is available, what the conditions in the Delta are,” he said. “So, we’re working on both ends – the adult population and where they’re spawning, and we’re also having a lot of progress on figuring out that it appears the Delta is extremely important. When conditions are right in the Delta is when we have a big recruitment year for juvenile flounder.”

Powers said regulation changes have also been a factor in the flounder rebound. The ADCNR’s Marine Resources Division (MRD) reduced the daily bag limit to five fish with a 14-inch minimum total length and completely closed the flounder harvest to commercial and recreational anglers for the month of November.

“Flounder normally start moving offshore during the first cold front,” he said. “That’s why the state has imposed the November closure, because that’s when the fish are staging in the bays and sounds and are about to move offshore. They move offshore in November and December to do their business.”

Powers said when the flounder eggs are fertilized, they move back toward inshore waters on the tide flow, especially with north winds, which causes the bottom currents to move north with the eggs and larvae in tow. The movement into the estuaries occurs mostly from January through March.

“Where in the Bay those little flounder are has always been a mystery,” he said. “It seems most of them like the lower salinity areas up the Bay and into the rivers and the Delta. Then in April, May and June, those juveniles will be moving to the grass and all over the bottom. We’ve always thought that after the adults go offshore and spawn that they trickle back into the bays and estuaries. That is the case for most, but it seems a good proportion just stay offshore. We’re learning a whole lot more about that cycle.

“Flounder numbers are definitely improving. A lot of that is because of the new regulations, and the environment is improving. The last three years have been good, but we’re not quite there yet because we’re not seeing enough older fish in the population. It’s mainly a female fishery because the males rarely get bigger than 13 inches.”

MRD Director Scott Bannon said he has received the same reports of numerous flounder from divers around Perdido Pass and in offshore areas. He also heard that both recreational and commercial fishermen are catching more flounder.

“We have seen an increase in recreational landings,” Bannon said. “Also, prior to 2019, when we made the flounder regulation changes, our commercial fishermen were struggling to have good catches. We implemented the 40-fish bag limit, and now they are easily obtaining their 40 fish, which is why we are considering an increase for them. Those are both positive, that both our commercial and recreational sectors are seeing increased catches.”

Powers said redfish, especially the bull reds that are 26 inches and larger, have an interesting story, with anglers harvesting an abundance of the popular species. With funding from the Coastal Conservation Association (CCA) of Alabama and ADCNR, the USA team has been able to attach acoustic tags and monitor flounder, speckled trout and redfish through the hydrophone network for the past 15 years.

“We have colleagues with all these listening stations,” he said. “Over the last three years, we tagged (acoustic) more than 100 bull reds, and those tags will live 10 years. About 90 percent of the fish tagged last year off Dixey Bar (Fort Morgan), come back to Dixey Bar. That’s really cool. Our colleagues in Louisiana are reporting that off the Chandeleur Islands and Lake Pontchartrain they have heard from about 20 of those fish. We know that our fish are off our shoreline, but they’re going to Louisiana and coming back. Now we know the bull reds, the spawners, off Alabama, Mississippi and Louisiana are kind of the same group. We haven’t heard about any going into Florida waters, and we’re not hearing from any Florida fish.

“Every now and then we will see a fish kill with the bull reds that we think is caused by low dissolved oxygen in the water. So, it’s nice to see that high survivorship in the past two years. We now harvest more redfish from the Gulf than ever before. Even before the big blackened redfish craze, that Gulf-wide harvest was 12 million pounds. Now, we’re at 16 million pounds, and we think it’s sustainable because very little of that 16 million pounds is coming from the big spawning population. When we got in trouble in the late 90s, most of the harvest was the big spawners.”

Powers thinks protecting the spawning population is the key to sustainability for a number of fisheries.

“It’s that cryptic biomass that we have when you do not harvest spawners,” he said. “I also think that’s what’s going on with red snapper. The Great Red Snapper Count found this cryptic biomass, which is always there producing eggs. That looks like that might be the wise way to manage fisheries.

“The more we learn, the quicker we give this information to ADCNR, and the quicker they change fishing regulation to take into account that knowledge. It’s been a real good cycle between ADCNR and South.”

Harvest of redfish is prohibited in federal waters, and Powers thinks fishing regulations for state waters should protect that spawning population.

At the March 8 Conservation Advisory Board meeting in Montgomery, Bannon will propose the elimination of the exemption of one red drum larger than 26 total inches from the daily bag limit, which Powers endorses. The current slot limit on redfish is 16 to 26 inches.

“I’m in total agreement to not harvest redfish above 26 inches,” Powers said. “Catch big bulls, take amazing pictures and throw them back.”

Bannon pointed out how much the recreational fishing pressure has increased in the past decade. He said that about 140,000 saltwater licenses were distributed in 2019, which increased to more than 214,000 in 2023.

“We have to be mindful of how many hooks are in the water and mindful of how that impacts the species,” Bannon said. “Redfish is a high value species in Alabama, and anglers enjoy catching them. So, it’s a proactive measure to eliminate the oversize exemption and keep those spawners in the system and allow anglers to retain those slot limit fish, which the majority of the public keep to eat.”

Powers said the speckled trout fishery appears healthy, but there’s still a great deal to learn about tripletail as well as sheepshead.

“What we see from the trout fishery is good,” he said. “We try to get a sense if we are seeing big trout in the rivers and Delta. This past year was definitely one of the better years for trout.”

Bannon agreed with Powers’ take on the trout fishery.

“We get a lot of positive feedback on trout catches,” Bannon said. “We appear to be in a good place.”

Powers said there is a great deal of data to be collected on tripletail and sheepshead in the next three years that will provide a better understanding of the health of those species.

“There’s so much we don’t know about tripletail and sheepshead. We have no evidence to suspect there is a problem with tripletail, but its popularity is growing so much. And we know the sheepshead harvest has been increasing. People are learning to target that species. It’s not that we’re seeing or hearing anything overly concerning with tripletail and sheepshead; it’s just that we’re trying to be proactive to learn more.”

Bannon said he hopes anglers who participate in the fishery in Alabama appreciate what is available.

“We’re blessed to have the participation and the stock levels we have,” Bannon said. “We’re excited about the research and finding out more about tripletail, which is a highly sought after species. And we’re going to find out more about sheepshead, which has become a more popular species that anglers target. To be proactive, we are going to recommend a bag limit reduction from 10 fish to eight fish. That’s a healthy bag and still allows for some reduction in the overall harvest.” 

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