Searching for Mangroves in the Florida Panhandle

Searching for Mangroves in the Florida Panhandle

In 2005 I was leading a field trip with high school students in a salt marsh on Santa Rosa Island near Pensacola Beach.  As we explored a brackish water creek, we came across a three-foot red mangrove tree, prop roots and all.  To say we were surprised and excited would be an understatement.

Most know that mangroves are trees that can tolerate seawater and grow along estuarine shorelines across the tropics, including south Florida.  They can form dense forests that support all sorts of aquatic and terrestrial wildlife.  They need calm protected waters to establish themselves but once established are excellent at protecting shoreline communities during hurricanes.  However, they cannot tolerate cold weather, only surviving freezing temperatures for one or two nights.

The red mangrove.
Photo: University of Florida

Growing up in Pensacola we would often find red mangrove propagules (seedlings) washed ashore arriving from the tropical parts of the Gulf.  They were generally on the Gulf side of Santa Rosa Island and Perdido Key but never germinated.  If they were carried into the estuary, and found a protected lagoon to begin germination, they would not survive our winters.  This is what made finding an established three-foot mangrove in a lagoon off Santa Rosa Sound in 2005 so surprising.


Mangrove propagule washed ashore. Photo: Rick O’Connor

Historically mangroves were not found north of Tampa Bay.  However, in recent decades they have become established as far north as Cedar Key.  Trying to determine whether the mangrove we found was the northern most in Florida I found that they were also expanding along the east coast of Florida as far north as St. Augustine, and there were records in the Jacksonville area.  Many attribute this to climate change.  Our winters are milder than they were when I was a kid, and this may be leading to what many are calling the “tropicalization of northern Gulf of Mexico”.  Not only mangroves, but other historically south Florida species, such as snook and bonefish, have been reported along the panhandle.

In 2017 I was leading another high school group on a field trip in a salt marsh in Big Lagoon State Park.  We found a germinated seedling of a red mangrove doing very well.  We explored more and found seven others in the nearby area.  How many more were growing in the Pensacola Bay area?

A small red mangrove growing in Big Lagoon near Pensacola FL
Photo: Rick O’Connor

We partnered with a research team from Dauphin Island Sea Lab who was looking into this as well.  The team included extension agents and specialists from Florida and Mississippi-Alabama Sea Grant, as well as biologists from the National Estuarine Research Reserves in Mississippi, Alabama, and Florida panhandle.  Each county/region selected 10 transect sites that had the highest probability of mangroves to monitor each year.  Mangroves appear to be established on some of the Mississippi barrier islands, as well as in St. Joe Bay.  Individuals have been reported from Bay County.  A ninth mangrove was found in Escambia County but a hard freeze in 2018 killed them all.  Since then, one young multi-year red mangrove was found on NAS Pensacola.  It died in the hard freeze of 2023.  Despite the hard freezes, those established in St. Joe Bay seem to be holding on.  I decided to make a visit and see.

A red mangrove growing at NAS Pensacola. Photo: Whitney Scheffel.


Black mangroves growing near St. George Island in Franklin County.
Photo: Joshua Hodson

Wading out from the buffer preserve with Gulf County Sea Grant Agent Ray Bodrey, we found relatively large patches of mangroves, and seeds suggesting active expansion was ongoing.  But I noticed the species we were seeing were black mangroves.  I mentioned to Ray that what we had seen in Pensacola were red mangroves.  He said that the red mangroves have a hard time here as well.  Black mangroves are more tolerant of cold weather, and it is they who are establishing these large patches.  There are reports of large patches of mangroves on the Mississippi barrier islands – and they are the black mangroves as well.  I know that black mangroves have been established in the Chandeleur Islands in Louisiana for decades.  I am convinced that if black mangroves seeds were to reach protected lagoons in Pensacola Bay, they would probably do well here as well.

I continue to conduct our transects each year in the Pensacola Bay area.  I have a couple of trained volunteers helping me but could always use more.  If you think you have seen a mangrove growing in the Florida panhandle, we would love to know and document their location.  We know they are established in Gulf County, so our focus is now Escambia to Bay counties.  If you think you have seen one, contact me at or your county Sea Grant Agent.

Oyster Predators in the Florida Panhandle

Oyster Predators in the Florida Panhandle

Even though oysters have a hard shell that even humans have a hard time opening, they do have natural predators in our waters that can easily slurp up a couple dozen. Your usual oyster slurping suspects include oyster drills, blue crabs, and fish (such as the black drum).  In this article, we will focus on the 3 major predators that contribute the most toward natural mortality in oysters here in the Florida Panhandle.

The Oyster Drill

When it comes to the marine snail world, oyster drills would win an oyster-eating contest. Oyster drills (Urosalpinx cinerea) are marine gastropods that grow to sizes of 0.5 – 1 inch. Oyster drills can be found all along the Atlantic coast of North America and the Gulf of Mexico, and they have been accidentally introduced into Northern Europe and the West Coast of North America. These small but mighty snails have become specialized in consuming oysters. Using chemotaxis, they locate their prey oyster. Once they find it, they secrete an enzyme to soften a portion of the oyster shell. Once softened, they drill into the shell and siphon out oyster meat. Oyster drills have been known to occur in great numbers when the environmental conditions are prime and can wipe out not only entire oyster beds but also clam beds. Oyster drills do have natural predators as well, but these predators also consume oysters.

Oyster Drill
An Oyster Drill (Urosalpinx cinerea) – Barnegat Bay Shellfish

The Blue Crab

Most of us know about the very tasty blue crab (Callinectes sapidus), but many do not know that it is a major consumer of oysters, especially on an oyster farm. Blue crabs are a decapod crab (meaning 10 legs) of the swimming crab family Portunidae. Blue crabs can indeed swim and their last leg on each side has developed into what are called paddle fins.  Juvenile oysters are the main target for blue crabs, but they have been observed eating adult oysters when given the opportunity. On an oyster farm, blue crabs can get into an oyster bag when they are very small. Once inside, they have an all-you-can-eat buffet of oysters, and can quickly wipe out a bag of oysters. Oyster farmers have to be very cautious and must either remove the blue crabs manually or dry their bags out in hopes of destroying any blue crabs. Blue crabs can easily break open a juvenile oyster, but for them to consume an adult oyster, they will wait for it to open to feed before shoving a claw inside of the shell to keep the oyster open. Once they have their claw in the shell, they will use their other claw to consume the oyster.

Blue Crabs on a table
Blue Crabs (Callinectes sapidus) Pulled Out Of Oyster Bags – Thomas Derbes II

The Fish

Even though oyster-eating fish like black drum (Pogonias cromis) and sheepshead (Archosargus probatocephalus) are much bigger than snails and crabs, they tend to contribute less to oyster mortality on oyster farms. However, during certain seasons wild oysters and other shelled invertebrates can contribute up to 33% of a black drum’s diet (more here). Fish will usually congregate around oyster beds and farms, but they are more interested in consuming oyster predators like crabs and snails. The black drum is a fish that was built for oyster consumption. While black drum lack sharp teeth, they have crushing plates in their throat that can crush an oyster shell which allows the drum to eat the oyster meat. Many oyster farmers welcome these fish on their farms as a free source of anti-fouling and predator deterrent (in the form of consumption).

Black Drum
Black Drum (Pogonias cromis) Caught On A Whole Oyster – Thomas Derbes II

There are many more oyster predators, but these are the top 3 in terms of threat and ability to consume/do detriment to oyster beds and farms in the Florida Panhandle. While oyster drills rank up towards the top, crabs and fish can also greatly contribute to natural mortality.


Flimlin, G., & F Beal, B. (n.d.). Major Predators of Cultured Shellfish.

The Florida Master Naturalist Program

The Florida Master Naturalist Program

Kayaking over seagrass beds and stingrays, hiking among pitcher plants, boating past diving ospreys, and meeting hundreds of fascinating, like-minded people—these are just some of the great experiences I’ve had while teaching the Florida Master Naturalist Program. More than 20 years since its inception, the Florida Master Naturalist Program (FMNP) has inspired the creation of dozens of similar courses in other states and proven itself to be one of the most popular outreach programs to come out of UF IFAS Extension.

Kayaking Santa Rosa Sound in Navarre is one of the highlights of our Coastal Systems FMNP class. Photo credit: Carrie Stevenson, UF IFAS Extension

The mission of the FMNP is simple—to promote awareness, understanding, and respect of Florida’s natural world among Florida’s citizens and visitors. I have always felt strongly that if you want people to care about something, they need to understand it. And to really understand something, you need to experience it. I know my own passion for science and ecology was ignited early on by teachers who took us outside and helped us encounter the many wondrous surprises in the natural world. With the FMNP, we seek to do just that.

Master Naturalist students conduct field work in small groups. Photo credit: Carrie Stevenson, UF IFAS Extension

Over a span of 40 hours in 6-7 weeks, we spend about half our time with classroom presentations and the other half in the field, seeing the plants, animals, and ecosystems we discuss in class. In addition to classes and field trips, students produce a final project and present it to the class. These can range from labeled collections and slide presentations to building bird houses and new trails. The program is composed of three 40-hour core courses; Coastal, Upland, and Freshwater Systems. Seven “short courses” with 24 hours of class/field time include the Land Steward series (Conservation Science, Habitat Evaluation, Wildlife Monitoring, and Environmental Interpretation) and the Restoration courses (Coastal Restoration, Marine Habitat Restoration, and Invasive Plants). Locally, we try to rotate the core modules every couple of years and incorporate the short courses periodically. Registration includes a detailed course manual and, upon completion, FMNP patch, certificate, and pin denoting area of expertise. There are a handful of scholarships available for those interested in applying to offset costs.

Master Naturalist students walk “The Way” boardwalk in Perdido Key. Photo credit: Carrie Stevenson

The classes do not count towards university credit but are an excellent certification and professional development opportunity that many will list on a resume. While we’ve had ecotour operators, park rangers, environmental consultants, teachers, and archaeologists participate, most of our FMNP students are not professionals in the field. They come from every background imaginable but share an interest in the outdoors. Because we meet weekly, class members often form long-lasting friendships during the courses.

Information on upcoming classes in northwest Florida and all around the state is available online. Classes range from fully in-person to hybrid and online options. FMNP classes are restricted to adults 18 and over, but a new “Florida Youth Naturalist” curriculum has been designed through our 4-H program for young people. For more information on that, check out their website.

Floating Oasis in the Bays; Oyster Farms and Their Ecological Benefit

Floating Oasis in the Bays; Oyster Farms and Their Ecological Benefit

You might have seen a floating oyster farm while driving over Garcon Point Bridge or along Scenic Highway. Many people know them for the beautiful, tasty oysters they produce, but those farms have a major ecological benefit that many aren’t aware of. First, the oysters in those cages act as a very efficient water filter, filtering upwards of 30 gallons per day. The floating farms also act as an oasis for other marine creatures, from crustaceans to finfish, and can help increase the biodiversity in the area. Oysters are also great at sequestering carbon into their shells. Today, we will go over these ecological benefits and proper etiquette when maneuvering around the farms to enjoy some of the ecological benefits of the oyster farm.

Pompano on an oyster farm
Florida Pompano Caught Off an Oyster Farm – Thomas Derbes II

Besides being tasty, oysters are very well known for their ability to filter massive amounts of water in a single day. Research has shown rates of up to 50 gallons per day in a laboratory setting, but they filter upwards of 30 gallons per day in the wild. With most oyster farms in the area having more than 500,000 oysters on their farm, that’s more than 15,000,000 gallons of water per day per farm! Oysters can filter out any excess sediments from the water, forming them into small packets and depositing the sediment on the bottom of the bay, keeping the sediments from being re-suspended. This is very beneficial to any bay or estuary as eutrophication (More Here on Eutrophication) has been an issue in almost every bay in the southern United States.

Another benefit to oyster farms is that it is a floating oasis for all types of marine creatures. Blue crabs and stone crabs are a common threat to oysters, and they love to congregate around oyster farms waiting for an easy meal from a dropped oyster or oyster spat on cages. Common bay fish, like the Spotted Seatrout, Sheepshead, and Red Drum, have been known to hang out under the cages consuming smaller finfish and crabs, but some uncommon fish like Tripletail and Florida Pompano also patrol the cages looking for a meal. Because of its ability to hold all types of fish, fishermen love to fish around the oyster farms. Fishing around oyster farms is allowed, but most farmers want the boats to stay on the boundary of the farm and not inside of it. This is due to there being lines under the surface of the water that could potentially damage any lower unit and can cut free a line of cages. Also, it is against state law to be within the boundary of the farm if you are not an authorized harvester of that lease, and I have personally seen FWC enforce those rules. As a seasoned oyster farmer once told me “We know our farm holds fish and it is okay for them to fish the farm, heck put out some blue crab traps around it, but do not mess with the cages and stay outside of the boundary and we can all live in harmony.”

Oyster Farmer holding a Tripletail fish
Tripletail Caught Off An Oyster Farm – Brandon Smith

Last but not least is the ability of oysters to sequester carbon and excess nitrogen into their shells and pseudofaeces (aka bio-deposits). Carbon and nitrogen sequestration is a crucial service provided by oysters that helps battle global climate change. Just as they do with excess sediments, they deposit excess carbon and nitrogen into bio-deposits that accumulate on the bottom, keeping them from being re-suspended into the waters. Oyster reefs are currently on the decline around the world, and their decline has “resulted in a forfeiture of several ecosystem services” including carbon and nitrogen sequestration and water filtration. (More Here on Carbon Sequestration)

While oysters might be tasty, we have learned about some of the ecological services oysters provide to an estuarine environment. From water filtration to increasing biodiversity to carbon/nitrogen sequestration, oysters are a major benefit to any estuary and can help fight climate change and eutrophication. Next time you see an oyster farm or reef, give oysters (and farmers) a little appreciation for their hard work in helping make the world a healthier place!

From Seed to Shuck – More Oyster 101

From Seed to Shuck – More Oyster 101

When you hear about oyster farming, you typically hear the word “seed” and how it is highly important to the future of the farm. While it might not be a typical seed that produces agricultural crops like corn, this seed is a living, breathing (albeit in the water) organism that produces a beautiful, cupped oyster. Depending on market size demand and requirements, it could take anywhere from 8 to 24 months to reach “shucking ready” size. Let’s take a dive into the timeline of an oyster, from seed to shuck.

Cooler Full of Seed Headed To Farm
A cooler full of R6 oyster seed headed out to the farm – Grayson Bay Oyster Company

Oyster farmers typically buy seed from an oyster nursery or hatchery, where they carefully spawn male and female oysters together in individual spawning chambers. Depending on the farmer’s needs, they can produce either diploid or triploid oyster larvae (more on triploids next week). These larvae are free-swimming for the first 2-3 weeks of their life until they develop into pediveligers (Oyster 101). Hatcheries will, for lack of better terms, mix the pediveligers with very tiny grains of ground-up oyster shells. These pediveligers will then attach to a single grain and begin to form into a “seed” oyster. Seed costs range and vary from year to year, and this cost is usually one of the biggest financial purchases oyster farmers can make. Seed is sold by size, starting at 6 millimeters (typically called size R6), and by increments of 1,000. Hatcheries and nurseries are located all along the Gulf Coast, but Florida law requires seed put in the Gulf of Mexico waters and estuaries must come from Gulf of Mexico hatcheries, and the same rules apply to Atlantic waters.

Oyster Seed
Oyster Seed (>R16) – Thomas Derbes II

Once purchased, these seed oysters make it to their homes in beautiful nutrient-rich waters and grow at a steady rate, and can reach an overall size of 2 inches in 4 to 9 months. During those months, the seed are filtering gallons of water per oyster per day, helping sequester carbon in their shells and consuming large amounts of plankton and algae that could contribute to the eutrophication of the bays. Oyster farmers will check on the seed almost weekly, changing bag mesh sizes and sorting the seed by size. Farmers will also take this opportunity to check for any oyster predators and swiftly evict them from their all-you-can-eat buffet. Sorting is done by using a “tumbler” that has a long drum with holes of varying sizes. This tumbler also helps clean the oyster and chip away at the lip of an oyster shell, causing the oyster to grow deeper and create a beautiful cup.

Farmed oysters do not have a size limit, but most farmers stick to a 2.5 to 3-inch size oyster. These oysters have filtered over 7,000 gallons of estuary water individually and sequestered a very generous amount of carbon, in the form of calcium carbonite (more here), in their shells in their first year of life. Once deemed ready for harvest, farmers will pull them out of the water and get them quickly in the fridge, following strict biosecurity guidelines and regulations to provide a safe product year-round.

Oysters of varying size
Some oysters are fast growers! These were apart of the same spawn. – Thomas Derbes II

And there you have it, from seed to shuck. With the holidays coming up, and seafood sometimes being a part of the holiday plans, reach out to the local oyster farmers in your area to reserve a dozen or two for your favorite uncle. You can also wow the crowd with this very fancy mignonette recipe below! 

Lemon Champagne Mignonette

Juice From 2 Local Meyer Lemons (They’re in Season!)

1 Shallot Chopped Finely

½ cup Champagne Vinegar

¼ cup Red Vinegar

1 tbsp each of Green and Pink Peppercorns 

24 Local Farm Raised Oysters (For the Environment!) 

1.       In a bowl, add the juice of Meyer lemons and shallots. Let it marinate for 10 minutes.

2.       Add champagne vinegar, red vinegar, and peppercorns to the lemons and shallots.

3.       Chill for at least 30 minutes in the fridge.

4.       Shuck oysters and top with freshly made mignonette. Enjoy!

Panhandle Terrapin Project 2023 Report

Panhandle Terrapin Project 2023 Report

Diamondback terrapins are the only resident turtle within brackish water and estuarine systems.  Their range extends from Massachusetts to Texas but, prior to 2005, their existence in the Florida panhandle was undocumented.  The Panhandle Terrapin Project was developed to first determine whether terrapins exist in the panhandle (Phase I) and, if so, what is their status (Phase II and III). 

Mississippi Diamondback Terrapin (photo: Molly O’Connor)

The project began at the Marine Science Academy at Washington High School (in Pensacola) in 2005.  Between 2005 and 2010 the team was able to verify at least one record in each of the panhandle counties.  For Phase II we used what we called the “Mann Method” to determine the relative abundance of terrapins in each area.  To do this we needed to conduct assessments of nesting activity in each county.  In 2012 the project moved from Washington High School to Florida Sea Grant.  At that time, we developed a citizen science program to conduct Phase II of this project.  Effort first focused on Escambia and Santa Rosa counties, but in recent years has included Okaloosa County.  Florida Sea Grant now partners with the U.S. Geological Survey (based out of Gulf County) to assist with Phase II and lead Phase III, which is estimating populations using mark-recapture methods, as well as satellite tagging to better understand movements and habitat use.  The focus of Phase III has been Gulf County, but tagging has occurred in Okaloosa and Escambia counties. 

Over the years we have trained 271 volunteers who have conducted thousands of hours of nesting surveys and helped obtain a better picture of the status of diamondback terrapins in the Florida panhandle.  Here are the 2023 project results. 

Results from 2023

We trained 67 volunteers; 35 (52%) of which participated in at least one nesting survey.

The volunteers conducted 196 surveys logging 212 hours. 

During those surveys terrapins (or terrapin sign) were encountered 43 times; a Frequency of Encounter (FOE) of 22%.

Three terrapins were tagged.  Two from Okaloosa and one from Escambia.  All but two of the nine primary survey beaches saw nesting activity (78%).  One new nesting beach was discovered. 

Escambia County

Two nesting beaches.  47 surveys. 7 encounters (FOE = 15%).

The Mann Method assumes the sex ratio is 1:1 (male: female) but recent studies suggest the ratio may be as high as 5:1 (male: female).  Based on these two rations the number of terrapins estimated to be using these beaches ranged from 4-36. 

One terrapin (“Dollie”) was tagged.  Fire ants and torpedo grass were reported on some beaches. 

Santa Rosa County

Three nesting beaches.  68 Surveys. 14 encounters (FOE = 21%).

The number of terrapins estimated to be using these beaches ranged from 6-30.

No terrapins were captured, though one was seen nesting.  No invasive species were reported from the nesting beaches. 

Okaloosa County

Four nesting beaches. 67 surveys.  21 encounters (FOE = 31%). 

The number of terrapins estimated to be using these beaches ranged from 2-66.

Two terrapins were tagged (“Kennedy” and “Molly”).  Phragmites were reported from all beaches. 

Walton County

Walton county currently does not have a volunteer coordinator and surveys are not occurring at this time.  We are working with an individual who may take the lead on this. 

Bay County

This team is just beginning and currently there are no primary beaches.  The team focused on five beaches encountering terrapin nesting activity on one of them.  They conducted a total of 14 surveys encountering terrapin tracks on 1 of those (FOE = 7%).  The estimated number of terrapins using this beach ranged from 4-12. 

Baldwin County Alabama

Due to the proximity of terrapin habitat and nesting beaches at the Alabama/Florida line, and the possibility of terrapins using habitat in both states, a team was developed in Baldwin County Alabama this year.  The team began conducting Phase I surveys and encountered one deceased terrapin.  No nesting beaches have been identified at this time. 


The results of this year’s surveys suggest that, based on the number of nesting beaches we know of, there are anywhere from 2-66 terrapins utilizing them.  Again, two of the primary beaches did not have nesting activity this year.  USGS tagging studies will provide better population estimates and a better understanding of how these animals are utilizing these habitats.  The current population estimate for Gulf County is a little over 1000 individuals and most are showing relatively small range of habitat utilization, although two individuals in the western panhandle moved from one county to the neighboring one. 

Training for volunteers occurs in March of each year.  If you are interested in participating, contact Rick O’Connor –