The open sandy beach is one of the hardest habitats to live in on a barrier island. There is no where to hide and almost nothing to eat. Add to this the direct wind and waves from the Gulf of Mexico and you have a barren landscape with continuous climate and ocean energy. But creatures do live here.
The beach is void of plant life and takes a well adapted animal to reside here.
Phot: Rick O’Connor
Before we go further let’s define a few terms. The beach is actually the dry sandy portion of this environment. The area where the sand squeaks as you walk through it, the place where you set your chairs, umbrellas, and lunch for your day at the beach. The berm is the harder packed sand near the waters edge. The place where you like walk when you walk the beach (it’s easier) and the waves wash over every few seconds. Living in these two would be very different. Second, we will define resident and transient. A resident is a creature who actually resides there. A transient is just passing through but lives somewhere else.
As you look across the beach you will notice there is NO WHERE to hide from the elements… except beneath the sand. One of the more common creatures who lives beneath the is the ghost crab (Ocypode quadrata). This crustacean digs burrows down to the water table where they can keep their gills wet and this can be as deep as four feet. On these flat beaches they are easy target for predators. They have several ways to deal with the problem. (1) Their compound eyes are on stalks above their head to give them a wider, and longer, range of view. (2) They are white in color and blend in with the quartz sand well. (3) They are more active at night, nocturnal. (4) They are very fast.
The trick to speed is to break contact with the ground. If you were to ask someone “what is the fastest way to get to Los Angeles?” They would answer “flying”, and this would be correct. Birds are some of the fastest creatures around. They fly. They lift off the ground and do not touch again until they reach their destination. It does not get any better than that. Cheetahs are very fast as well. But if you watch them in slow motion, you will see they are basically leaping from one point to the next. They touch the ground very few times over a certain distance. They are trying to fly but cannot. If look at video of a human, or centipede, or slug. Not sot good. Crabs are crustaceans and by definition they have 10 legs. When they move across the surface, they usually use eight of those (two being their claws). The same is true for the ghost crabs. But when they decide to run, they only run on three of them. They raise the other five above their heads. This means fewer legs touching the sand which means they are faster.
The common ghost crab. Photo: Virginia Institute of Marine Sciences
Food is another issue. Due to direct high wind (filled with salt), plants do not grow on the beach. Hence the classic food chain (plant – herbivore – carnivore) cannot exist. So, what do ghost crabs eat? They are scavengers. They emerge from their burrows, usually at night, to seek what dead creatures the tide may have washed in. Post storms are particularly good feeding times. Surf fishermen along the Gulf beach often catch hardhead catfish and, not liking them, often toss them on the beach to die. In the evening the ghost crabs will drag these to the entrance of their burrows where they feast for quite a while. They eventually clean to fish to the bone leaving their “hard head” (the skull). When you look at the skull from underneath it appears to be Jesus on the crucifix. These skulls are often collected and sold in novelty stores as “crucifix fish”.
The bones in the skull of the hardhead catfish resemble the crucifixion of Christ and are sold as “crucifix fish”.
Photo: Rick O’Connor
Another prize for ghost crabs are sea turtle eggs. Sea turtles are obvious transients to the beach environment, coming here only during nesting season. The females usually approach the beach close to where they were born at night. She will labor her way across the beach to the first dune line, though some will lay theirs in the open beach area. She could spend several hours digging a hole three to five feet deep. Loggerhead Sea Turtles (the most common on our beaches) simply dig a hole. The Green Sea Turtle will use her flippers to dig a form for her body before digging the nest. She will deposit about 100 eggs before burying them and returning to the Gulf. Ghost crabs, and other beach transients like coyotes, fox, and raccoons, will find and raid these nests.
Tracks left by a nesting Green Sea Turtle. Courtesy of Gulf Islands National Seashore.
The wrack (a line of debris that includes seaweed, shells, and other flotsam from the Gulf) offers a variety of food for ghost crabs. Another who is often found scavenging the wrack are shore birds. There are numerous species of terns, gulls, pipers, and plovers that will pick through the wrack for food.
The berm is a tougher place to make home. You are in the surf zone and must deal with breaking waves every few seconds. As you might expect, there are no plants here, and very few animals. Those that do reside here bury in the sand knowing that the surf will most likely expose them and could carry them to another location. The two most common animals in this zone are the mole crab and the coquina.
The mole crab is often called a “sand flea”.
Photo: Rick O’Connor
The mole crab (Emerita talpoida) is also known by surf fishermen as the “sand flea”. It is a small oval shaped crab that has a hard paddle like telson to dig into the wet sand tail first. With its head exposed it will extend antenna that are covered with small hair-like structures designed to collect plankton from the water that covers it when the waves come in. The surf often exposes them, but they flip over and dig back in very quickly.
The coquina (Donax variabilis) is a small clam that comes in a variety of colors (hence it’s species name). Like all clams, it has a fleshy foot which it uses to quickly dig into the wet sand covering most of its body. Like the mole crab, it exposes its head into the surf extending two fleshy tubes called siphons that draw water into the clam where it can collect planktonic food.
Coquina are a common burrowing clam found along our beaches.
Photo: Flickr
Predators do exist here, but they are not residents. They would include transient fish that come close to shore waiting for the surf to wash these small animals into the Gulf. One of the more common is the Florida Pompano. Surf fishermen like to use “sand flea” baskets, dragging them through the sand near the waters edge to capture the mole crabs for bait seeking these tasty fish. Others would include an assortment of shorebirds like sand pipers and plovers who run to the wet sand when the surf recedes back into the Gulf probing for the mole crabs and coquina, then quickly running back towards the beach when the surf returns.
A variety of shorebirds utilize the wrack. Photo: Rick O’Connor
The diversity of life in the beach-berm zone is not high, but this is a tough place to make a living. Ghost crabs, mole crabs, and coquina clams have all adapted to living here and have done quite well. But more wildlife prefers the dunes. It is a little easier there and the next stop in Part 5 of this series.
The classic model of ecological succession begins with new land. This could be new land formed by a sand bar, or a new landscape formed after a volcanic eruption, but new land none the less. Then the pioneer community begins. Based on the model, the plants need to be first, herbivores cannot survive unless there are plants already present. When we teach students about maintaining aquaria, we actually begin with the bacteria community needed to breakdown the organic waste from the plants and animals when they arrive. So, some would say “begin there”. As the pioneer plant communities form, the pioneer herbivores arrive. This would be followed by more advanced communities of plants and then more advanced communities of animals, until you reach the climax community.
Beach
The open beach is how most barrier island ecosystems begin awaiting the arrival of the pioneer community.
Phot: Rick O’Connor
But science understands that it is more complicated than that. Each new member of the community would make chemical and physical changes to the environment that could allow new species to thrive while other existing ones die off. Then those would make changes as well and the process is ALWAYS changing. That there is never a true climax community, change is happening all of the time. Then there was the case of Mt. St. Helens.
St. Helens erupted in 1980 destroying 229 square miles of habitat. This new landscape gave ecologists an opportunity to witness ecological succession firsthand. Like everyone, they expected the pioneer plant community to arrive first, and so on. But in some areas, it was the carnivores that arrived first, completely against the classic model. These carnivores apparently survived the blast and began to wonder the new landscape. How did they survive? They survived by feeding on each other. But eventually the pioneer plants did arrive, all creatures “got in line” and the world was good once again. The interesting thing was it did not happen the way they thought it would. It also shows the resiliency of life.
Mt. St. Helens destroyed almost 300 square miles and produced new habitat.
Photo: University of Washington.
So, how did this process unfold on our barrier islands? I do not know. You would guess that it unfolded the way the model suggests – pioneer plants first, pioneer animals, more complex plants, more complex animals, barrier island ecosystem. But as we have seen, there are several ways it could have started.
What we do know is that the animals who made it to the islands had to do so by either swimming, flying, or walking. For those who reached our islands on foot – beach mice, ants, etc. this must have happened at a time when the island was still connected to the mainland.
The Choctawhatchee Beach Mouse is one of four Florida Panhandle Species classified as endangered or threatened. Beach mice provide important ecological roles promoting the health of our coastal dunes and beaches. Photo provided by Jeff Tabbert
For the swimmers, short swims like Indian Pass could be achieved by several species. Deer and other small mammals may have been able to do this. I have seen bears swim and assume coyotes could make short swims. As the island continued to move with the tide and currents, the distance to the island would have increased. The pass across the mouth of our estuaries, or across the intracoastal waterway, is now daunting for many of these swimmers – but not all. I have seen eastern diamondback rattlesnakes swim across the ICW and have heard bears can still make this trip. For the flyers, these distances do not seem to be an issue. They easily, and often, do so.
Eastern diamondback rattlesnake swimming in intracoastal waterway near Ft. McRee in Pensacola.
Photo: Sue Saffron
If you imagine the early days of an island being low elevated sand, the new wildlife arrivals would face a daunting landscape. Burrowers, such as ghost crabs, could easily make a living here. Their burrows protect them from the elements and being scavengers, they would feed on anything the Gulf washed ashore – something they still do. Sea turtles and shorebirds could easily use the sand bars for nesting, and probably preferred it due to the few predators around. But eventually, the pioneer plants would become more established, allowing selected herbivores (who could survive in low elevation sand) to move in. Next the dunes would form, providing new habitat (read part 2 of this series). Additional herbivores, if they could reach the island, could now become established and at some point, the carnivores would enter the picture.
The line of seaweed and debris along the surf zone is called wrack. Photo: Rick O’Connor
There would initially be a finite amount of space for inhabitation and competition for that space and its resources would be high. Some would be more adapted to the environment than others, or physically stronger, or have a higher reproductive rate, to give them an edge over the others and the island wildlife community would begin. This community would include such things as insects, worms, amphibians, reptiles, birds and mammals. The marsh habitat would include aquatic species such as snails, clams, crabs, shrimp, and fish. All would have had to be able to reach the island, find a suitable habitat for their needs, find suitable food, and out compete others who had made the trip across as well. I was asked once as a college student – “who is a rhinoceros’s greatest competition?” It was an oral exam, and I was very nervous. My mind began reeling in all directions trying to think of what a rhino would have to compete for and WHO would be their greatest competitor. And then, with a little discussion from my professors, it dawned on me. Their greatest competitor would be another rhino. The other rhino would be seeking the same resources, habitat, and mates as the original one. Your first problem is with your own kind. And so, it would be for barrier island wildlife.
The bizarre looking armadillo enjoys a walk on the beach.
Photo: Rick O’Connor
With the arrival of humans, with their bridges and boats, additional creatures would be able to reach the islands and play a role in the competition, but that is another story, and we will discuss this more down the road. In Part 4 we will look at the species that have inhabited the beaches of our barrier islands.
The habitats of a barrier island are defined and driven by the plant communities there. Seeds from the mainland must first reach the new island and they can do so using a variety of different methods. Some come by wind, some by water, some by birds and other wildlife. Some of these germinate, some do not. Those that do, do so on a sandy island with little or no relief and must deal with the winds off the Gulf, which has salt spray. Many of these mainland plants cannot tolerate this and never make it. But some can… and do.
The dune fields of panhandle barrier islands are awesome – so reaching over 50 ft. in height. This one is near the Big Sabine hike (notice white PVC markers).
These early plant communities are known as the pioneer community – meaning the earliest settlers. In the process of succession pioneer communities are made of creatures that can tolerate the harshest conditions, the early days of ecosystem development. There are usually few nutrients, extreme climatic conditions, and for the animals, few prey to select from. But these pioneers are adapted to survive in these conditions and over time alter the conditions so that other creatures can move in.
For the barrier islands, grasses seem to be the plants who do best in the early stages of succession. Though small shrubs and trees may reach the island, the high winds and salt spray will not allow growth. There are numerous species of grasses that can live here, the most famous are the sea oats (Uniola paniculata). This grass can be found on the smallest of barrier islands. Their fibrous root system runs beneath the ground sprouting new grasses all over. Their seed heads blow with the wind starting new populations of plants on other locations and the landscape is soon dominated by them. However, there are other species as well. Panic grass (Panicum amarium), salt hay (Spartina patens), and beach elder (Iva imbricata) to name a few. All these grasses can tolerate the wind and salt spray as well as the low nutrient, low rainfall often found on these islands. They also all have fibrous roots systems that not only connect grasses across the land scape but also trap blowing sand – forming dunes.
The primary dune is dominated by salt tolerant grasses like this sea oat. Photo: Rick O’Connor.
The dunes closest to the Gulf are dominated by grass due to the higher winds and salt spray there. These are called the primary dunes and create one of the first habitats on the island for wildlife. The primary dunes vary in height and how far from the Gulf they range but they do form a wind break for portions of the island landward of the Gulf.
Here smaller shrubs and plants like seaside golden (Solidago sempervirens) and seaside rosemary (Ceratiola ericoides) can grow. With less wind their seeds will germinate and survive. What wind is still there forces the plants to grow in a round shape resembling green sheep on a white field, instead of white sheep on a green field. My professor referred to them as “beach sheep”. This area of the barrier island is called the secondary dune and includes other species such as false rosemary (Conradina canescens), square flower (Odontonychia corymbosa), and sandhill milkweed (Asclepias humistrata). Though they cannot tolerate the high winds as grasses do, they do have to tolerate climatic extremes and low rainfall.
Small round shrubs and brown grasses within the swales are characteristic of the secondary dune field.
Photo: Rick O’Connor
These secondary dunes vary in elevation and can become taller than the primary dunes. In the low areas between dunes are areas where freshwater water can collect and form ephemeral ponds. These areas are known as swales and create unique habitats much sought after by some wildlife. More bog like plants grow here such as water dock (Rumex orbiculatus) and marsh pink (Rhexia nashii) but also includes the carnivorous plants like the sundew (Drosera rotundifolia). There are many insects who used these ephemeral ponds and many spiders and sundews to take advantage of this.
Behind the larger secondary dunes, the wind is even less, and the dune wind breaks higher. Here trees can germinate, if they can tolerate the climatic conditions, and grow. Though the species that grow out there are some of the same you find on the mainland, here they grow differently. Barrier island trees tend grow out, not up, to avoid direct contact with wind and salt spray. And, when they do reach the wind the portion of tree directly facing the wind tends to be stunted in growth, giving it the appearance that someone has “combed” the tree back towards the bay – something they call wind sculpting. Trees that seem do well in what they call the tertiary dune include sand live oak (Quercus geminata), pine (Pinus sp.), and magnolia (Magnolia grandiflora). Yaupon holly (Ilex vomitoria) and even cactus like the prickly pear (Opuntia humifusa) and the devil’s joint (Opuntia pusilla) can be found growing here.
The top of a pine tree within a tertiary dune.
Photo: Molly O’Connor
Tertiary dunes are some of the largest on the island, with elevations reaching 50 feet or more. These provide excellent wind breaks from the Gulf and allow the formation of salt marshes along the bay side shoreline. Marshes are habitats dominated by grass, but these grasses must be able to tolerate periods emersed in salt water, at least at high tide. Close to the dunes the marsh is dominated by dense stands of black needlerush (Juncus roemerianus). In some locations within the needlerush marsh are areas of bare sand known as salt pans. These are low areas within the marsh where water remains when the tide recedes. These small marsh ponds begin to evaporate in the intense sunlight and the salinity increases to a level where it kills off much of the plant life leaving an area of bare sand. These salt pans are used by some wildlife on the islands. Eventually you will reach the waters edge where smooth cordgrass (Spartina alterniflora) grows. This marsh grass can tolerate water for longer periods than needlerush and supports both island wildlife and estuarine fisheries.
A finger of a salt marsh on Santa Rosa Island. The water here is saline, particularly during high tide. Photo: Rick O’Connor
As you can imagine, the process of establishing the pioneer community of grasses on a new, small sand bar, to an island filled with dunes and vegetation takes time – years, decades, maybe centuries – but eventually it will reach what we call the climax community and provides a variety of habitats to support wildlife.
In part 3 we will begin to look at how animal species colonize the islands as these habitats form.
To let everyone know how the battle against this invasive plant in the panhandle is going
To encourage everyone along the coast to keep searching, reporting, and removing it.
Can you actually eradicate an invasive species?
MAYBE
But… you must find and begin to manage it early. What many call Early Detection Rapid Response (EDRR) – and beach vitex is just that in the state of Florida.
For those not familiar with the plant, it is called beach vitex (Vitex rotundifolia). It is native to the Pacific coast of Asia, extending from North Korea to Australia. This suggest that it can tolerate cold weather, something that has kept many south Florida invasive species at bay in the Florida panhandle, but not this one.
Vitex beginning to take over bike path on Pensacola Beach. Photo credit: Rick O’Connor
It likes dry sandy soils and open sunny areas – our beaches are perfect. It begins with a taproot and forms runners that cross the surface of the sand in all directions, ALMOST 360°, but not quite. The runners are herbaceous at first and form blueish-green ovate shaped leaves and a cluster of beautiful lavender flowers in the spring and early summer. As the plant grows it becomes more woody and can form a shrub growing between three and four feet high. In the fall, after the cold fronts begin, the flowers become small gray seed pods. Each pod contains four seeds, and the plant can produce up to one million seeds/m2. These are viable for several months and can tolerate salt water for that period as well.
The plant may have been introduced as early as 1955 but was certainly here by the 1980s. During that period the state of South Carolina decide to try it in dune restoration after a series of strong hurricanes. That is when it raised its ugly head and let us know that it is not a plant we want on our coast.
Beach Vitex Blossom. Photo credit: Rick O’Connor
It grows aggressively forming large monocultures within the dunes. It is allelopathic, meaning it releases chemical compounds that can cause the decline of plants around it, this would include our beloved sea oats. Being a taproot plant, not a fibrous one like the sea oat, the integrity of the dunes to protect from storms is weakened. Becoming a shrub, it can also shade the sand keeping other native plants from sprouting and could impact both the survival of sea turtle hatchings and the listed beach mice around the Gulf.
The plant was first reported to us in Pensacola around 2014 by a birding couple we know in Gulf Breeze, Florida. It was growing on Fair Point near their home. They told us they had it under control on their property but that it was most likely coming from Pensacola Beach on Santa Rosa Island – so, we took a look – and we found it.
Since that time, we have found it in other coastal counties along the Florida panhandle and are trying hard to (1) remove it as fast as we find it and (2) educate others so they can help.
We just completed our annual survey event we call HALLOWEED. We only surveyed Pensacola Beach and the portion of the Gulf Islands National Seashore called Naval Live Oaks in Gulf Breeze. Here are the results from the 2022 HALLOWEED…
12 volunteers worked between 2-4 hours logging 41 total hours last Friday.
We have updates on the Pensacola Beach Survey – Naval Live Oaks results coming soon!!
95 sites of beach vitex in the bay area
57 of those (60%) are on Pensacola Beach (surveyed)
25 (26%) are at Naval Live Oaks (will need to be updated)
6 (6%) are on Navarre Beach (were not surveyed)
3 (3%) are in Gulf Breeze (not surveyed)
2 (2%) are on Perdido Bay (not surveyed)
2 (2%) are on Perdido Key (not surveyed)
Of the 57 sites on Pensacola Beach…
30 (32% of the total; 52% of sites on Pensacola Beach) are on NE Pensacola Beach – north of Via DeLuna Drive – and east of Casino Beach
24 (25% of the total; 42% of sites on Pensacola Beach) are on SE Pensacola Beach
2 (2% of the total; 4% of sites on Pensacola Beach) are on NW Pensacola Beach
1 (1% of the total; 2% of the sites on Pensacola Beach) are on SW Pensacola Beach
All 3 sites on WEST Pensacola Beach are GREEN – have been removed and have not returned; no survey of the west end of the island was conducted today – but based on current log – there is no beach vitex on west end of Pensacola Beach.
Of the 54 sites on the east end –
34 (63%) are on private property
20 (21%) are on public lands
Of the private properties –
24 (71%) have been either completely removed or have been treated and in the process.
10 (29%) have not been removed or treated – it is not illegal to have beach vitex and is up to the homeowner whether they want to manage it or not.
Of the public lands –
15 (75%) have either been completely removed and have not returned; or have been treated.
5 (25%) have not been removed or treated – it is up to us to make this change – and we will next spring.
We do hope to get a survey of Perdido Key completed by the end of the year.
We are also planning another annual removal event we call WEED WRANGLE for early spring 2023. We will need volunteers help to do this. If interested in helping, contact Rick O’Connor (roc1@ufl.edu; 850-475-5230 ext.1111).
As for the rest of the panhandle here are the records in EDDMapS as of October 2022.
Escambia County FL – 44 records
Santa Rosa County FL – 4 records
Okaloosa County FL – 31 records
Walton County FL – 0 records
Bay County FL – 0 records
Gulf County FL – 1 record
Franklin County FL – 4 records
Wakulla County FL – 0 records
Jefferson County FL – 0 records
We are SURE this is under reported and we need your help to update these records as well as remove these plants before we are out of the EDRR phase and eradication is no longer an option. Again, contact me (Rick O’Connor) at the contact above if you would like to help.
In recent weeks there have been reports of large masses of jellyfish along the Gulf Coast. I have actually heard people state “I would rather be in the water with 100 sharks than 100 jellyfish”. Maybe that is true from some. Honestly, it seems dealing with sharks could be easier. Jellyfish are just there in a swarm. The more you try to move them away, the more they come towards you – it is like trying to avoid the smoke from a campfire.
But jellyfish exist and people sometimes have to deal with them. The thing they hate about them, of course, are their painful stings. As Jimmy Buffett puts it – “They are simple protoplasm – clear as cellophane – they ride the winds of fortune – life without a brain”. This is prreeettttyyyyy close.
Jellyfish are common on both sides of the island. This one has washed ashore on Santa Rosa Sound.
The “cellophane” jelly material is called mesoglea and it is a protein-based material that is 90% water. Lay a jellyfish on a deck and see what is left at the end of the day – not much. The bell undulates rhythmically controlled not by a brain but by a series of nerves – what some scientists call a “nerve net”. At the base of the bell is a single opening – the mouth. There are no teeth and whatever they swallow enters a simple gut where digestive enzymes do their work. But it is the only opening – so, waste material must exit through the same opening. Yes… they go to the bathroom through their mouth. Nice eh…
Then there are the tentacles – those lovely tentacles. These are armed with small cells called nematocysts that harbor a small dart tipped with a drop of venom. Each nematocyst as a small trigger which, when bumped, will fire the dart injecting the venom. When you bump a tentacle, you are literally bumping hundreds of these nematocysts and receive hundreds of drops of venom. Some species hurt, some do not. Those that hurt are no fun.
So, why SO many at one time in one place?
Most jellyfish feed on small food. Those food sources tend to multiple when the water is warm (and it is warm right now) and there are lots of nutrients in the water. When we have heavy rain (and we have had heavy rains this year) the runoff introduces large amounts of nutrients to the system. Warm nutrient rich water mean increase in jellyfish food, which in turn means increase in jellyfish. With winds and tides working together (and we saw this with the recent front that passed through), the jellyfish are shoved into smaller locations. In recent weeks that has been close to shore and the thick masses of jellyfish we have witnessed.
They do fly the purple flags when jellyfish are spotted. It us unusual for them to be a problem on both the Sound and Gulf sides. So, usually if they are bad on the Gulf side, you can move your beach day to the Sound and be fine. And remember – this too shall end. It won’t last forever.
