This sounds similar to the idea that has been discussed about protecting some species of sharks. Do we really want to do this?
It reminds me of an interesting situation that was created when they passed the Marine Mammal Act in 1972. The law seemed simple enough. Citizens wanted to protect our marine mammals – such as whales, dolphins, and manatees. But it also included the polar bear, a dangerous animal. If you lived in a community where polar bears existed, and had one enter town that could possibly be a threat to the citizens, could you shoot it? A colleague of mine had a brother who worked with Alaska Fish and Game. We asked this question. He told us that – yes, if you were threatened by one you would shoot it. But you would have to defend yourself in court that it was defense and that you were not actively hunting the bear.
It seems odd to some that we would even consider protecting a creature that is potentially lethal to humans. But, as has been said so many times before, though they are potentially lethal, they rarely are. Rattlesnakes are different from polar bears in they do not seek us out when they are near us. They actually try to avoid us. In the United States only 5-6 people die each year from venomous snakes bites1. Comparing this to the number who die in car accidents, gun violence, or opioid overdose, there is no comparison. So, though the potential is there it is a very low risk. We can also note that many who bitten by snakes were trying to catch or kill the animal.
On the other side of the coin, these animals do us a service by controlling disease caring rodents. When predators select and kill prey, they tend to select one that is easy to catch and kill. Most predators not only have teeth, but hands and claws to grab the prey. The only thing a snake can do when it sees a rodent is grab it with its mouth and hold on. Many snakes do this, almost 90% of those in Florida do. But a few have venom. This can be injected into the prey so that the snake does not have to hold on, making the process much easier. It makes sense for snakes to have venom and is surprising that more do not. However, this venom was meant for killing prey, not for defending against predators. And rattlesnakes, like other venomous snakes, do not want to use it on humans if they can avoid it. As my professor told us in college venom is “expensive”. It is a complex cocktail of proteins they must produce, and they do not want to waste it.
So, though it seems strange that a state or federal agency would even consider protecting dangerous animals, they do. These creatures play a vital role in the ecology of local systems and if their numbers decline that role is not filled and the spin-off results could have larger negative impacts on us.
The U.S. Fish Wildlife Service has been petitioned to list the eastern diamondback rattlesnake (Crotalus adamanteus). This animal inhabits several habitats within the coastal southeastern United States. The National Council of Air & Stream Improvement, Inc. – a scientific research organization that provides technical information on environmental issues concerning forestry and forestry products – is conducting a survey to better understand its distribution and habitat preferences. They are asking people to report sightings of this snake. You can do so by visiting the following link. Please take photos.
The eastern diamondback rattlesnake is a classic serpent found in xeric habitats like barrier islands and deserts. They can be found in all habitats on barrier islands.
Photo: Bob Pitts
The word “jellyfish” tends to initiate a similar response in most people – “scream”, “run”, “this is going to hurt”. Being stung by a jellyfish is not pleasant and is something most would prefer to avoid. Our beaches warn us when they are out by flying a purple flag.
When exploring the seagrasses, this is not the first animal people thing they will encounter. Few associate jellyfish with the seagrass community. But within any community there are those we call residents (they reside here) and those we call transients (just passing through). It is the second group that we can place most jellyfish, at least the ones we are concerned about.
The sea nettle.
Photo: University of California at Berkley.
Jellyfish are animals, but not your typical ones. They are obviously invertebrates but differ from most others by having radial symmetry (having a distinct top and bottom, but no head nor tail). They possess ectoderm and endoderm (so, they have a skin layer and some internal organs) but they lack the mesoderm that generates systems such as the skeletal, circulatory, and endocrine. Though they do not have a brain, they do have a simple nervous system made up of basic neurons and some packets of nerve cells called ganglia. They seem to know when they are not in the upright position and know when they have stung something – which initiates the feeding behavior. But they are pretty basic creatures.
When you view a jellyfish the first thing you see is the “bell” and the tentacles – we always see the tentacles. The bell is usually round (radial), could be bell-shaped, or could be flat. It is made of a flexible plastic-like jelly material called mesoglea. Most of the mesoglea is actually water. When you place most jellyfish on the dock and come back in a few hours there may be nothing but a “stain” of where it was. It completely evaporated. There are some exceptions to this, like the moon jelly and the cannonball jelly, who leave thick masses of mesoglea for long periods of time.
Image: Wikipedia.
If you look closer at the “bell” you will see shapes within the mesoglea. Some are stripes, and may have color to them, others look like a clover leaf. These are the gonads of the animal. Jellyfish are hermaphroditic (the gonads can produce both sperm and egg), and they reproduce by releasing their gametes into the water column when triggered by some environmental clue to do so.
Around the edge of the “bell” many have a thin piece of tissue called the velum that can undulate back and forth and allow the jellyfish to swim. Swimming can involve moving up or down in the water column, or turning around, but the swimming action is not very strong and the tide and current actually plays a larger role in where the animals go – like pushing them through a seagrass bed.
Under the “bell” is a single opening, the mouth, that leads into a simple gut (the gastrovascular cavity). This serves as the stomach of the creature. But there is no anus, when the jellyfish has digested its food, the waste is expelled through the same opening – the mouth. This is called an incomplete digestive system.
Jellyfish are predators and hunt small creatures such as baitfish. Though they know whether they are upside down or not, and may be able to detect light, most have no true eyes and cannot see their prey. Some species may be able to detect scent in the water and undulate their velum to try and move towards potential food, but most drift in the water and hope the tide carries them to dinner. To kill their prey, they extend tentacles into the water. These tentacles are armed with stinging cells known as nematocysts. Each nematocyst holds a coiled harpoon with a drop of venom at the tip. They are encased in a cell membrane and are triggered when an object, hopefully food, bumps an external trigger hair that will fire the harpoon. This will then trigger the release of many nematocysts and the potential prey will be “stung” by many drops of venom. The venom can either kill or paralyze the prey at which time the tentacles bring it to the mouth. Many jellyfish have venom that is painful to humans, like the sea nettle and moon jelly, others have a mild venom that we do not even notice. Some have a very strong venom and can be quite painful, like the Portuguese man-of-war which has put some in the hospital. The famous box jelly of Australia has actually killed humans. We do have box jellies in the Gulf of Mexico, but they are not the same species.
This box jellyfish was found near NAS Pensacola in November of 2015.
Photo: Brad Peterman
As the tide pushes these transients through the seagrass meadows, their tentacles are extended and small baitfish like juvenile pinfish, croakers, and snapper become prey. But there are resident jellyfish as well.
With the Phylum Cnidaria (the stinging jellyfish) there are three classes. Class Scyphozoa includes the bell-like jellyfish that drift in the water column with extended tentacles – what are referred to as medusa jellyfish. But there are two other classes that include benthic (bottom dwelling) jellyfish called polyps.
Polyp jellyfish resemble flowers. The “bell” part is a stalk that is stuck to a rock, pier, or seagrass blade. Their tentacles extend upwards into the water column giving the creature the look of a flower. Instead of drifting and dragging their tentacles, they hope to attract prey by looking like a hiding place or other habitat. The sea anemone is a famous one, and a good example of the polyp form. But it also includes corals and small polyps known as Hydra. Hydra are tiny polyps that are usually colorless and can easily attach to a blade of turtle grass. Here they extend their tentacles into the water column trying to paralyze small invertebrates that are swimming by or grazing on the epiphytes found on the grass blades.
The polyp known as Hydra.
Photo: Harvard University.
Another jellyfish that drifts in the current is Beroe, what some call the “football jellyfish” or “sea walnut”. This a relatively small blob of jelly that lacks tentacles but rather has eight rows of cilia/hair (ctenes) along its side that move quickly and move this animal through the water. But like their medusa cousins, not against the tide or current. These jellyfish do not sting, they lack nematocysts, and hence are in a different phylum known as Ctenophora. Kids often find and play with them when they are present, and they are luminescent at night. These stingless jellyfish feed on small plankton and each other and are another transient in the seagrass community.
The non stinging comb jelly.
Florida Sea Grant
There are certainly species of jellyfish to be aware of and avoid. But as you look deeper into this group there are harmless and fascinating members as well. Most of these Hydra are very small and hard to see while snorkeling, but they are there. Another creature to try and find while you are exploring and play “seagrass species bingo”. Have fun and stay safe.
Many who visit a seagrass bed for fishing or snorkeling, see many forms of marine life while there. There are numerous small silver fish darting in and out of the grass, an occasional stingray half buried in the sand waiting to ambush prey, and sometimes a horseshoe crab crawling along looking for a meal. One seagrass community creature they are not aware of, even if they are in front of them, are the sponges.
Those who are not familiar with the creature we call the sponge may think of the synthetic ones purchased at grocery stores and made in a factory somewhere. They are usually colored to match your kitchen or bathroom. Those who are familiar with them associate them more with reefs. Some reef sponges can become quite large and often they are quite numerous out there. But they do not register as a member of the seagrass community with most people. But they are out there.
A vase sponge.
Florida Sea Grant
From a taxonomic point of view sponges are interesting. What is a sponge?
Is plant? animal? fungi?
Well, to classify it using the characteristics of each, we can rule out plants. Plants have cell walls and organelles within some cells to conduct photosynthesis. This is not the case for sponges.
We can also rule out fungi. Though fungi do not photosynthesize, they do have cell walls, and sponges do not.
This leaves animals. Yep… they are animals.
Once you classify it as an animal the next step is to declare it either a vertebrate or invertebrate. Based on the definition of each, this would be an invertebrate – there is no backbone.
Invertebrates can be further broken down based on their symmetry and which germ layers they possess in the early stages of development – the larval stages.
Most invertebrates are categorized as either having radial or bilateral symmetry. Radial invertebrates have a top and bottom (dorsal and ventral) side, but no head or tail (anterior, posterior). Bilateral invertebrates will have all four. For some sponges, you can find radial symmetry, for others there is no symmetry at all – those would be asymmetrical.
Bilateral creatures have a distinct “head” end (anterior) and a “tail” end (posterior).
With germ layers you can have ectoderm (the outside cell layer), endoderm (the inside), and mesoderm (the middle layer). Each germ layer develops different structures as the larva grows. If the creature is does not have a specific germ layer, they will not develop those specific structures. Sponges have no germ layers. They do not have true skin, no internal organs, no circulatory, musculature, or nervous system. That is a sponge… the simplest form of animal life on the planet.
The three germ layers of animal development.
When you look at a sponge you do see structure. There are different forms (species) of them and they can be distinguished from each other and named – like “vase sponge”, or “barrel sponge”. But when you look inside of them many have a lot of tissue with canals and channels running all through them. Like what an ant colony would look like underground.
A closer look shows that the exterior wall is very porous (giving them their phylum name Porifera). The water enters these pores and moves all through the massive highways of channels running through the creature. Eventually the water exits the sponge at the top through large pores (or one large pore) called the osculum. The currents that drive this water movement are generated by the flagella of small cells called choanocytes (collar cells). They line the channels by the thousands. Rotating their flagella, they create water movement the way a rotating fan causes air movement. The movement is from the environment into the sponge. Here they collect food from the water (small microscopic creatures and other forms of organic debris), and oxygen.
The anatomy of a sponge.
Flickr
There are other cells within the lining of the channels called amoebocytes who assist with reproduction. They can encase genetic material (cells) within a hard matrix called a gemmule and “toss it” into the currents where it will exit through the osculum, drift in the ocean currents, and form a new sponge elsewhere. Being simple creatures, they can certainly reproduce asexual by simple cell division. Fragments of sponge will also generate new sponges.
The skeleton that holds these cells into the form we see is a series of hard structures called spicules. Spicules come in different shapes and under the microscope appear to look like thorns, are the “jacks” of a common game played by baby-boomers when they were kids. Some are solid, others a little more flexible, and the material used to make these spicules are used to divide sponges into different classes.
Sponge spicules.
Image: NOAA
Spicules made from calcium carbonate are hard and scratchy, they are in the Class Calcarea. These are often sold as “luffa’s”. Those made of the more flexible-spongin are in the Class Demospongia and is the largest class of sponges. These are often sold as “bath sponges” and are softer. And then there is the Class Hexactinellida – the “glass sponges”. Their spicules are made of clear silica and they look like they are made of glass. They are more common in the deeper part of the ocean and are beautiful.
Glass sponges are beautiful.
Photo: NOAA
In the seagrass beds of the panhandle, you will find sponges from the “bath sponge” group. One common one sold at the Gulf Specimens Lab in Panacea is called “Green Finger Sponge”. As you move through the grasses you will encounter these anchored near the base of the grass. They are usually dark in color, often a dark green almost black, and when opened appear yellow or orange on the inside.
They are full of creatures. Sponge channels provide excellent hiding places for the small creatures who graze on the epiphytes found on the grass blades. All sorts of small crustaceans and worms can be found here. It is like a microhabitat within the grassbed system itself.
Green finger sponge common in panhandle grassbeds.
Photo: Gulf Specimens Lab
The relationship between sponge and grass is complicated. Sponges filter the water, improving water clarity which seagrasses need. However, seagrasses are excellent at trapping and holding sediment, which also improves water clarity but these same sediments can plug the pores of sponges which they need to feed. It is sort of a love/hate relationship between them.
The purpose of this series is to educate you on some of the members of the seagrass community. Sponges are one such creature and most people do not notice them. But they are interesting creatures if you take a look.
At their December 2021 meeting, the Florida Fish and Wildlife Conservation Commission (FWC) passed two rulings designed to enhance the conservation of diamondback terrapins, a small estuarine turtle.
As of March 1, 2022, no one can possess a diamondback terrapin without an FWC permit.
As of March 1, 2023, all recreational crab traps in Florida must have a 6×2” funnel opening, or a By-Catch Reduction Device to make the funnel opening 6×2”.
This article discusses the recreational crab trap ruling. We will discuss the What, Why, How, When, and Where of this ruling.
What…
The new ruling calls for all recreational crab traps in Florida waters to have a 6×2 inch funnel opening, or a By-Catch Reduction Device that creates a funnel opening of 6×2 inches, by March 1, 2023.
Why…
Diamondback terrapins are a species of special concern in the state. The diversity of sub-species is high, highest of any other state, but abundance is low. Research has shown that threats to terrapin populations include, loss of habitat and nesting beaches, nest depredation by wildlife, removal for the pet trade, and incidental drowning in crab traps. To help conserve this animal in our state the two rulings mentioned above were passed in 2021.
How…
By-catch Reduction Devices (BRDs) measuring 6×2” can be obtained from your local Florida Sea Grant Extension Agent. If you do not have a Sea Grant Extension Agent in your county extension office, they will direct you to the closest one. You will need to place the BRD on each of the funnel openings of your crab trap using zip ties. Your local Sea Grant Agent can show how to do this.
When…
All recreational crab traps used in Florida waters should have the 6×2 inch (or BRD in place) by March 1, 2023.
Where…
This is for Florida waters only.
If you have further questions concerning this ruling, please contact your local Sea Grant Agent at your local county extension office.
This orange plastic rectangle is a Bycatch Reduction Device (BRD) used to keep terrapins out of crab traps – but not crabs.
Photo: Rick O’Connor
No one species has altered the land, sea, and sky – as well as decreased the overall biodiversity of the planet in such as short time as has Homo sapien. Since we have arrived on this planet we have slowly dispersed across all continents, oceans, and even the polar regions. In our wake we have changed the landscape. Altering forests and changing waterways. We have built communities and cities and, in recent years, increased the amount of waste we produce to impact the land, water, and even change the climate. Our planet has encountered major changes in climate and habitats before – but not at the rate it is currently happening, and many are not able to adapt fast enough. Wildlife over much of the planet has declined due to our activities – and barrier islands are not an exception.
Humans have found our barrier islands. Photo credit: Lydia Weaver
Humans first arrived in the Florida panhandle a little over 10,000 years ago. Most of them built communities along our riverways and deltas. As with much of coastal wildlife, barrier islands were difficult places to inhabit. There is little freshwater, selected game to hunt (though an abundance of seafood – which they did seek), intense heat in the summer and cold in the winter, and tropical storms – where there were few places to hide. It appears humans did visit the islands but did not settle there. The early European colonists tried, but unsuccessfully – they had to moved inland.
In the Pensacola Bay area, the first settlements that were successful were fortifications placed there by the U.S. Army to protect the communities where people lived. These were brick fortifications that held up well against the storms, all built with large cisterns to collect freshwater for the troops stationed there. Soldiers accessed them using ferries.
In the early 20th century locals from Pensacola built a casino at what is now Pensacola Beach. There were casinos, boxing, and food vendors for those who made the day trip by ferry to visit the location.
The famous “beach ball” of Pensacola Beach marks the spot where the old casino once stood.
Photo: Molly O’Connor
Much of this early human activity had little impact on the island wildlife. Humans were concentrated in specific locations and did not / could not venture very far from them. But when automobiles became more commonplace with people, bridges soon followed, and things did begin to change. More cars meant more people, and the need for roads. These roads bisected the dune system and altered how they naturally progressed with wind and waves. Not only did dune dynamics change but dunes began to disappear with the new homes and hotels that were built.
A coyote navigates the roads that are now on our islands.
Photo provided by Shelley Johnson.
Homes, cars, and roads made life for several island creatures tough. Most of the shorebirds using the islands as nesting areas lay their nests on the sand. The white/speckled eggs blend in well with the white sand and the warm sand helped incubate them. There were fewer predators on these beaches and so, protection of the chicks was achieved more by driving off any potential threat by “dive bombing” them. This did not work with humans, nor their cars. The roads became hazards for them, and small chicks were often hit by cars. Today some species are threatened and have been given federal protection.
A variety of shorebirds utilize the sand as a nesting area.
Photo: Rick O’Connor
In recent years beaches houses have become true homes, with lawns and gardens. This alters the natural landscape even more. Along with the altering of the dune systems, this impacted many dune creatures like the beach mice. The species on Perdido Key is now considered endangered, and also has federal protection.
Additional housing, development, and roads led to additional needs in lighting in the evening. Many barrier island creatures need “dark skies,” but notably are the nesting sea turtles. In recent years 50-60% of sea turtle nests on our islands have had adults and hatchlings “disorient” towards the artificial lighting instead of the moon/star light that reflects off of the Gulf. This, along with other human related impacts like structures left in the sand at night, have caused a decline in these turtles and they too are now federal protected.
Turtle friendly lighting.
Photo: Rick O’Connor
You could not mention impacts by the human presence without mentioning solid waste – marine debris. Modern humans produce a wide variety of plastic products which we bring to the beach, and some of it ends up in the environment. Sea turtles, shore birds, and even manatees have been found either entangled in it or having ingested it. Much of this marine debris is problematic for the wildlife there.
Boxes providing garbage bags and disposal.
Photo: Pensacola Beach Advocates
Recently there has been an increased issue of pet cats that are allowed to roam the island at night. These pets (some strays) are known for the impact they can have on small wildlife like birds.
We were lucky in Escambia County during the 1970s to have the National Park purchase about 50% of the island as a National Seashore. This has provided a space for the island creatures and a great nature/cultural tourism destination.
Much of the west end of Santa Rosa Island has remained natural due to the presence of the Gulf Islands National Seashore.
Photo: Molly O’Connor
No one moves to the beach with the intent of harming wildlife, but our sense of changing things when we arrive – which we have been doing for some time – does impact them. The answer to this problem is to learn how to live, and develop, with the wildlife on the islands. The islands play a crucial role in protecting the mainland from storms and providing habitat for several unique species. Many of these species are beneficial to our lives by playing an ecological role in maintaining the island. It can be done.
I hope you have learned something new in this nine-part series on barrier island wildlife. If you have, please let me know by emailing roc1@ufl.edu. I hope you get a chance to explore our islands and maybe see some of these neat creatures.
The definition of an invasive species used by the University of Florida IFAS has three parts.
It is not native to the area.
Was brought to the area by humans; either intentionally or accidentally.
Is causing an environmental or economic problem, or somehow lower the community’s quality of life.
Florida is famous for its invasive species problems. Actually, every state in the country is battling this issue. In 2005 the estimated economic cost of invasive species in the United States was $137 billion annually. Looking at the Invasive Species Curve (below) you can see the most effective method of managing is to prevent them from coming in the first place. Easier said than done. International travel and commerce by plane and boat enters Florida every day, who knows what these are bringing with them. There is the legal trade, illegal trade, and the accidental hitchhiker. Though there are efforts in each state trying to prevent invasive species from entering, they do enter. Once they have arrived, resource managers move into what we call Early Detection Rapid Response (EDRR) in hopes of eradicating the species but at the very least containing them. It is a constant battle.
The Invasive Species Curve
Though separated from the mainland, our barrier islands are not immune to this threat. Humans travel to and from our islands all year round; we live on many of them. With us comes non-native species we both intentionally and accidentally bring. Some of these become invasive and can threated the wildlife of our islands. The state is divided into 15 Cooperative Invasive Species Management Areas (CISMAs). The western panhandle is under the Six Rivers CISMA, the eastern panhandle is under the Apalachicola Regional Steward Alliance (ARSA). Both CISMAs have developed a EDRR list for their area. As a member of the Six Rivers CISMA, I helped developed ours and below are the species considered the biggest threats to our island wildlife.
Florida CISMAs
Beach vitex (Vitex rotundifolia)
Beach vitex is native to the Pacific coast of Asia and was intentionally brought to the United States as an ornamental/landscape plant. It does well in open sunny areas, dry soils, along the coast – perfect for barrier islands. In the 1980s it was used for dune restoration in the Carolinas and that is when its invasive nature was first seen. Like all invasive species, there are few predators and disease, and so reproductive success is high. The species multiples and spreads rapidly, basically uncontrolled. Beach vitex is allelopathic, meaning that it creates an environment that can kill nearby plants and thus take over that area; sea oats are one species this occurs with. Its impact on wildlife could include the loss of required habitat and food source. It appears to have already impacted sea turtle nesting in the Carolina’s, and that threat exist here as well. It could also impact the ecology of the listed beach mouse.
I was first made aware of the presence of this plant in the Pensacola area in 2013. It was discovered on the shoreline of a private property on the Gulf Breeze peninsula in Santa Rosa County. It was suspected to have come from nearby Santa Rosa Island. A survey of the Pensacola Beach area found 22 sites where the plant existed. One was quite large, covering about 70% of the property. The others were small individual plants. Some were part of a homeowner’s landscape; others were on public land. At the time, beach vitex was not listed as an invasive species in Florida. Today it is and has also been declared a state noxious weed. A database search indicates there are currently 118 records in the state of Florida found in six counties. Four of those counties are in the Florida panhandle and include Escambia, Santa Rosa, Okaloosa, and Franklin. More in-depth surveys of the coastal areas, and islands, of the remaining counties in the panhandle may find more records of the plant. There are active projects in the Escambia/Santa Rosa area to manage it.
This yard on Pensacola Beach has become over run by vitex.
Cogongrass (Imperata cylindrica)
Cogongrass is native to Central and South America. It was brought to the United States accidentally through the Port of Mobile. It quickly spread across the landscape covering much of south Alabama, northwest Florida, and Mississippi. It now can be found in most of Alabama, a large portion of Mississippi, much of Louisiana and Georgia, some of the Carolina’s, Tennessee, and Virginia, and in every county of Florida. It is not only listed as an invasive species in these states, but also as one of the nation’s worst noxious weeds. It quickly covers pastureland. Being serrated and having silica with the grass blades it is not palatable to livestock, you can lose good pastureland when this invades. In natural areas and private timberland, it quickly covers the understory where it burns too hot during prescribed burning efforts and creates a situation where the valuable management method cannot be used. It is not a good plant to have on your land.
In 2020 we were made aware the plant was growing on Perdido Key in Escambia County. We are not sure how it got there but most likely from landscaping equipment that was not cleaned after working an inland area where the plant was present – this is a common method of dispersing the plant. Currently there are 456 records along the coast of the Florida panhandle. 404 of these are on coastal beaches and 52 are on our barrier islands. 44 of the island records are on Santa Rosa/Okaloosa Island, 4 at St. Andrew’s State Park, 1 on Cape Sand Blas, and 1 on St. Vincent Island.
What impact this plant will have on barrier island wildlife is not fully understood. But we know that it has not been beneficial within inland habitats and the potential of having a negative impact is there. Locally we will begin to survey for exact locations on the islands in Escambia County in 2023 and begin a management plan for those, as well as education outreach to reduce potential sources.
Cogongrass shown here with seedheads – more typically seen in the spring. If you suspect you have cogongrass in or around your food plots please consult your UF/IFAS Extension Agent how control options.
Photo credit: Mark Mauldin
Giant Salvinia (Salvinia molesta)
This is a new invasive species to our area and, until recently, was only found within our state in the panhandle. There are now 19 records found in 7 counties across the state; 10 of the 19 records are in Escambia County. This is a freshwater species that prefers quiet backwaters with high levels of nutrients. In our county the plant is concentrated in the upper arms of Bayou Chico. Though an estuary, Bayou Chico has relatively lower salinities than most of our other bayous – the plant is doing well there. The Florida Fish and Wildlife Conservation Commission (FWC) began management of this area a few years ago, but it is still there and seems to have spread to a nearby retention pond. The best guess as to method of dispersal were beavers seen moving back and forth between the water bodies. We plan to conduct surveys of other nearby retention ponds in 2023.
Though relatively new to Florida, it has had a large impact on the freshwater systems of Texas and Louisiana. I witnessed firsthand that impact at a lake near Shreveport LA where I was camping. This plant is a small one that floats on the surface of the water. It resembles duckweed but the leaves are larger. It had completely covered the surface of the lake and was kept out of the swimming area by using booms. There was no way to fish in the lake and moving through with a paddle craft would have been difficult. It is similar to water hyacinth covered waters. Though the swimming area was clear, the bottom had become “mucky”, and no one was swimming. All water recreation had stopped. The thick canopy covering the surface of the lake blocks sunlight so no submerged grasses can grow, the dead plant material decomposes and draws down the dissolved oxygen levels which could create fish kills.
Knowing this, FWC has a team focused on eradicating this plant from our state before such situations occur here. Though it will not reach our barrier islands by floating there (because of its dislike of salt water) if it DID reach any of the retention ponds near the homes, hotels, and condos, via landscaping equipment used on inland ponds, or some other method, it could be a real problem. And, as we have seen in Bayou Chico, wildlife could move it to the natural freshwater ponds on the island. We will begin surveys of all ponds on Perdido Key and Santa Rosa Island in 2023.
Giant Salvinia mats completely covering Bay County pond. This fast growing invasive can double in coverage every two weeks! Photo by L. Scott Jackson
The Brown Anole (Anolis sageri)
This small lizard from Cuba (also known as the Cuban anole) has been in Florida for some time. It most likely reached our shores accidentally by hitchhiking on a boat. With south Florida’s tropical climate, the lizard did quite well and began to disperse north.
I first encountered the creature on campus in Gainesville. Along west side of Ben Hill Griffin Stadium (The Swamp) are trees that are enclosed in wooden boxes – a sort “raised bed” look. When I looked in one of them there were numerous brown lizards scattering everywhere. I checked the next tree and found the same. I found the same in each of the tree boxes along that road. I then began to see them at the rest stops on I-10 between Pensacola and Gainesville. You would step out of the car and as you walked you would see numerous small brown lizards scattering everywhere. The same ones as in Gainesville – the brown anole. I then received a call from a resident on Innerarity Point Road near Perdido Key. She wanted to know what type of lizard she was now seeing in her yard. They were small, brown, had white spots (diamond-like patterns) on their backs and were EVERYWHERE. I asked for a photo, and eventually made a site visit, they were the brown anole. I then began to receive calls from other residents near Perdido Key, then from Gulf Breeze, then from the East Hill area of Pensacola. All the same. The brown anole had made it to Pensacola. Interestingly, when I was speaking to a garden club about invasive species, and was discussing this one, residents from the north end of the county had no idea what I was talking about. They had never seen them. They apparently were invading near the coast. Between 2018-2021 I was conducting a cottonmouth survey on Perdido Key for a Homeowners Association who was encountering a lot of them. At first the brown anoles were not there. Then, during the second year of surveying, I began to see them. The brown anole had reached the barrier island.
It is believed that the mode of dispersal is the same as how they reached Florida in the first place – hitchhiking. Most likely on landscape plants that were grown in south Florida, transported up here, and delivered to you. It is not quite clear how they may impact barrier island wildlife. We know where they show up the native green anole (Anolis carolinensis) begins to decline. Some studies show that the green anoles move higher up in the trees and shrubs where needed resources are limited, and the population will most likely not survive. I have watched green and brown anoles battle it out on my front porch (yes – I have brown anoles in my yard also). I have seen green anoles win these battles – but they seem to have lost the war. I seldom find them anymore. What changes may happen to wildlife on the barrier islands we will learn with time. Though I have not personally seen one on Santa Rosa Island, I am sure they are there – and probably on your barrier island also.
Cuban Anole. Photo credit: Dr. Steve A. Johnson, University of Florida
Cuban Treefrog (Osteopilus septentrionalis)
As with the brown anole, it is believed the Cuban treefrog reached our state hitchhiking on a boat. They too have been in the state for quite some time. But records in the Florida panhandle were non-existent. It was believed that the winters here too cold for them. But that appears to be changing.
I have had occasional calls about this frog over the last few years. In each case it was a single individual, hanging on their windows and glass doors, shortly after the homeowner had purchased new plants for landscaping. As with the brown anole, we believe this is a common method for spreading them. But as we mentioned, there was not much concern because our cold winters would keep this invasion at bay. Then there was a report of several Cuban treefrogs at a location on Tyndall AFB in Panama City. They appeared to be breeding and also appeared that they had overwintered. Dr. Steve Johnson (of the University of Florida) later confirmed this to be the first recorded breeding group in the panhandle. And the “love had begun to spread”. More accounts were being reported in the western panhandle. One community in Santa Rosa County found over 100 over the course of a year. Again, we think they are spreading with landscaping plants, or hitchhiking by other methods.
The issue with the animal is similar to that of the brown anole. It is much larger than our native treefrogs and likes to devour them. They are large enough to eat small native lizards and snakes as well. They produce a mild toxin in their skin that can irritate your eyes, nose, and even trigger asthmatic attacks. They have been found in toilets and are known to even plug the plumbing. They have also been found in electrical power boxes and have caused power outages. Overall, they are pain to deal with.
There are currently 28 records in the Florida panhandle. Though some have been found along the coast of our estuaries, there have been no reports on our barrier islands. Maybe we can educate the public on the hitchhiking issue and possibly keep them off the islands. We will be initiating a citizen science effort to monitor their locations on Pensacola Beach and Perdido Key beginning in 2023.
Cuban Treefrog.
Photo by: Dr. Steve Johnson
Invasive species, by definition, are a problem for barrier island wildlife. But another problem they are facing is the increase in humans. That will be the topic in part 9.
