Sea urchins are one of the more commonly encountered creatures when snorkeling in our seagrass beds. At times these little pin cushions can be found in great numbers. In some locations there have been too many and community events have been developed to remove some. In the western panhandle they have all but disappeared. But for many parts of the panhandle, they are a noticeable member of the seagrass community.
According to the Florida Department of Health, most sea urchin species are not toxic but some Florida species like the Long Spined Sea Urchin have sharp spines can cause puncture injuries and have venom that can cause some stinging. Swim and step carefully when snorkeling as they usually are attached to rocks, both on the bottom and along jetty ledges. Photo by L Scott Jackson
Sea urchins belong to the phylum Echinodermata. The term echinoderm means “spiny skin” and is a good name for this creature. This group also includes the sand dollars, sea cucumbers, and the most famous member, the sea stars. Echinoderms are considered advanced and primitive at the same time. Advanced in the sense of organ development, sensory perception, and food gathering. Primitive in the sense that they have radial symmetry, like many of the more primitive invertebrate groups; bilateral symmetry is considered more advanced. The entire phylum is marine, they have no freshwater, nor terrestrial members, and they do like the water salty – at least 20 parts per thousand, and some need it higher than that.
As mentioned, the sea stars are the “star” of the group. They usually have five arms that radiate from a central disk region. On top there are usually small knobs or bumps which are the remnants of their “spiny skin”. Some species, though none in our area, have elongated spines. Beneath the arms is a radial canal which houses a series of gelatinous suckers called tube feet. The sea star can fill these with water using a unique system called the water vascular system. The tips of the tube feet or concave and, when full of water, can create a suction cup that is used for pulling themselves along the bottom and for grabbing food. These canals all meet within the central disk in what is called a ring canal and the water that fills them is sucked in by the sea star through a screen-like structure on the top of the central disk called a madreporite (“screen sieve”). The central disk is where the mouth is located, and it is located on the bottom. Food is worked into the mouth, digested, and excreted through an anus on the top of the central disk. Most species have some form of eye at the end of each arm and have a good sense of smell and taste.
Sea stars are predators, collecting small organisms they are fast enough to catch (which is not many really). But they can also take on larger slow prey, like shellfish. When they approach an oyster, which is sessile and cannot run away, they will grab each of the valves (shells) of the oyster with one of their arms. They will draw water into their water vascular system creating suction on the tube feet and “stick” onto the shells. They will then force the oyster open. Once open they will invert their digestive tract out of their body in a process called evisceration, consume the oyster, then retract the digestive tract leaving two empty shells on the seagrass bed floor. These empty shells are often found by snorkelers – though there are other predators of bivalves.
The Florida Orange Sea Star.
Photo: Florida Sea Grant
Sea urchins differ from their sea star cousins in the way their body is laid out. Imagine you had a five-armed sea star laying on the ocean floor. Imagine taking each of the five arms and rolling them upwards so that the tips of each touch above the central disk. Can you imagine this looking like a ball? A sphere? Now cover the now exposed underside of the arms with long spines (quills) and the tube feet extend between the quills. You have a sea urchin.
Another difference would be the mouth. At the terminus of each arm near the mouth is a single tooth. With five arms, there would be five teeth. Scientists call this set of five teeth Aristotle’s lantern and the urchin uses this to scrap algae from rocks, shells, and grass blades. They are herbivores, moving along feeding on a variety of seaweed and seagrasses in the system.
There is concern with many snorkelers that the quills (spines) of the sea urchin are venomous. That is the case with some species around the world, but not in our area. That said, they are sharp, and the purple urchin (more common in our rock jetties and artificial reefs) hurts. Their quills are sharp and often break off in the skin causing discomfort, much like a splinter. You do not want to handle them, but if you do – handle them with care.
Sand dollars are close cousins of the sea urchin and are in the same class (Echinoidea). If you can imagine taking a round sea urchin and squashing it flat like a pancake, you have a sand dollar. There are also echinoderms in this group that are not as round as sea urchins, but not as flat as sand dollars and are called heart urchins, or sea biscuits. These can be found in grassbeds at the eastern end of the panhandle, but are more common in south Florida.
The sea cucumber is an echinoderm more often found in rocky or coral reef communities, but there are some found in the seagrass beds. To see the relationship between them and their cousins, imagine taking a round sea urchin, lie it on its side, and extended the body so that it is no longer a round ball but an elongated worm-looking creature… sea cucumber. These are primarily scavengers and deposit feeders within the community.
Sea Cucumber
Photo by: Amy Leath
Being a resident of the western panhandle, we have noticed a mass decline of echinoderms in our grassbeds. As a kid in the 60s and 70s we never saw large numbers, as they do in the eastern panhandle, but we did see them. Now they are gone. One suggestion as to why has been salinity. Our bay system over here has more river discharge than those further east and the lower salinity may not support larger populations. The increased development of the years, and the methods of dealing with stormwater, may have created a system that echinoderms do not like. Whatever the reason, finding sea stars and sea urchins in our grassbeds is rare.
The eastern panhandle still has them. And, at times, too many. In recent years there has been an increase in sea urchin populations in St. Joe Bay that has led to overgrazing of the turtle grass. This could lead to a decline in suitable habitat for bay scallops, which the community depends on economically. The state currently sponsors a “Sea Urchin Round Up” event using humans to help control the overabundance of sea urchins.
Echinoderms are a visible, and interesting, part of our seagrass community.
Most of us in the Florida panhandle realize how important seagrasses are to the ecology of our estuaries. Not only do they provide habitat for commercially important finfish and shellfish, but they also help trap sediments, remove nitrogen from the system, and slow coastal erosion. But seagrasses throughout Florida have suffered over the last 50-60 years from environmental stressors created by humans. There has been a large effort by local municipalities to reduce these stressors, and surveys indicate that these have been successful in many locations, but there is more to do – and there are things you can do to help.
Reduce Stormwater Run-off
Stormwater run-off may be the number one problem our seagrass beds are facing. With the increased development along the panhandle, there is a need to move stormwater off properties and roads to reduce flooding of such. Older communities may still have historic drain systems where rainwater is directed into gutters, which lead to drainpipes that discharge directly into the estuary. This rainwater is freshwater and can lower the salinity in seagrass beds near the discharge to levels the seagrasses cannot tolerate, thus killing them. This stormwater also includes sediments from the neighborhood and businesses that can bury grass near the discharge site and cloud the water over much of the system to levels where needed sunlight cannot reach the grasses. Again, killing the grass.
Most would say that this is an issue for the county or city to address. They should be redesigning their stormwater drainage to reduce this problem. And many municipalities have, but there are things the private homeowner or business can do as well.
One thing is to modify your property so that the majority of the rainwater falling on it remains there and does not run off. Much of the rainwater falling on your property falls on impervious surfaces and “stands” creating flooding issues. You can choose to use pervious surfaces instead. For larger businesses, you might consider a green roof. These are roofs that literally grow plants and the rainwater will irrigate these systems with less running into the street. There is a green roof at the Escambia County Central Office Complex building in Pensacola. To learn more about this project, or visit it, contact Carrie Stevenson at the Escambia County Extension Office.
The green roof on top of the Escambia County Central Office Complex in Pensacola.
For those buildings that cannot support a green roof, you can install gutters and a rain barrel system. This moves rainwater into a barrel (or series of barrels) which can then lead to an irrigation system for your lawn or garden. All of which reduces the amount entering the streets.
rain barrels can be used to capture rainwater and avoid run-off.
Finally, you can use pervious materials for your sidewalks, driveways, and patios. There are a number of different products that provide strength for your use but allow much of the rainwater to percolate into the groundwater, thus recharging the groundwater (our source of drinking water) and reducing what reaches the street.
Plant Living Shorelines
Coastal erosion is an issue for many who live along our waterfronts. The historic method of dealing with it is to build a seawall, or some other hardened structure. These structures enhance the wave energy near the shoreline by refracting waves back towards open water where they meet incoming waves increasing the net energy of the system. Something seagrasses do not like. There are many studies showing that when seawalls are built, the nearby seagrass begins to retreat. This increased energy also begins to undermine the wall, which eventually begins to lean seaward and collapse. Placement and maintenance of these hardened structures can be expensive.
FDEP planting a living shoreline on Bayou Texar in Pensacola.
Photo: FDEP
Another option is a softer structure – plants. The shorelines of many of our estuaries once held large areas of salt marsh which provide habitat for fish and wildlife, reduce erosion, and actually remove sediments (and now pollutants) from upland run-off. But when humans moved to the shorelines, these were replaced by turf lawns and, eventually, seawalls. Returning these to living shorelines can help reduce erosion and the negative impacts of seawalls on seagrasses. Actually, several living shoreline projects enhanced seagrasses in the areas near the projects. Not all shorelines along our estuaries historically supported salt marshes, and your location may not either. It is recommended that you have your shoreline assessed by a consultant, or a county extension agent, to determine whether a living shoreline will work for you. But if it works, we encourage you to consider planting one. In some cases, they can be planted in front of existing seawalls as well.
Avoid Prop Scarring While Boating
Seagrasses are true grasses and posses the same things our lawn grasses have – roots, stems, leaves, and even small flowers – but they exist underwater. Like many forms of lawn grass, the roots and stems are below ground forming what we call “runners” extending horizontally across the landscape. If a boat propeller cuts through them form a trench it causes a real problem. The stems and roots only grow horizontally and, if there is a trench, they cannot grow across – not until the trench fills in with sediment, which could be a decade in some cases. Thus “prop scars” can be detrimental to seagrass meadows creating fragmentation and reducing the area in which the grasses exist. Aerial photos show that the prop scarring issue is a real problem in many parts of Florida, including the panhandle.
The scarring of seagrass but a propeller. These can remain “open wounds” for years.
Photo: Rick O’Connor.
The answer…
When heading towards shore and shallow water, raise your motor. If you need to reach the beach you can drift, pole, or paddle to do so. This not only protects the grass, it protects your propeller – and new ones can be quite expensive.
If Florida residents (and boating visitors) adopt some of these management practices, we can help protect the seagrasses we have and maybe, increase the area of coverage naturally. All will be good.
If you have any questions concerning local seagrasses, contact your local Extension Office.
In Part 5 of this series, we looked at a group of invertebrates that few people see, and no one is looking for – worms. But in this article, we will be looking at a group that seagrass explorers see frequently and some, like the bay scallop, we are actually looking for – these are the mollusks.
With over 80,000 species, mollusk are one of the more successful groups of animals on the planet. Most fall into the group we call “seashells” and shell collection has been popular for centuries. There is an amazing diversity of shapes, sizes, and colors with the snail and clam shells found in coastal areas worldwide. As snorkelers explore the seagrass beds it is hard to miss the many varieties that exist there.
Seashells have been collected by humans for centuries.
Photo: Florida Sea Grant
One group are the snails. These typically have a single shell that is coiled either to the right or left around a columella. Some are long and thin with a extended shell covering their siphon (a tube used by the animal to draw water into the body for breathing). Others are more round and ball-shaped. Each has an opening known as the aperture where the animal can extend its large fleshy foot and crawl across the bottom of the bay. They can also extend their head which has an active brain and eyes. Snails lack teeth as we know them, but many do have a single tooth-like structure called a radula embedded in their tongue. They can use this radula to scrape algae off of rocks, shells, and even grass blades. Others will use it as a drill and literally drill into other mollusk shells to feed on the soft flesh beneath.
In the Pensacola area, the crown conch (XXX) is one of the more common snails found in the grasses. This is a predator moving throughout the meadow seeking prey they can capture and consume. Lighting whelks, tulip shells, and horse conchs are other large snails that can be found here. You can often find their egg cases wrapped around grass blades. These look like long chains, or clusters, of disks, or tubes, that feel like plastic but are filled with hundreds of developing offspring.
The white spines along the whorl give this snail its common name – crown conch.
Photo: Rick O’Connor
A close cousin of the snail are the sea slugs and there is one that frequent our grassed called the “sea hare”. This large (6-7 inch) blob colored a mottled green/gray color, moves throughout the grass seeking vegetation to feed on. When approached, or handled, by a snorkeler, they will release a purple dye as a “smoke screen” to avoid detection. Snails secrete a calcium carbonate shell from a thin piece of tissue covering their skin called a mantle. The genetics of the species determines what this shell will look like, but they are serve as a very effective against most predators. Most… some fish and others have developed ways to get past this defense. But the slugs lack this shell and have had to develop other means of defense – such as toxins and ink.
This green blob is actually a sea slug known as a sea hare. It was returned to the water.
Photo: Rick O’Connor
A separate class of mollusk are the bivalves. These do not move as well as their snail cousins but there are NO access points to the soft body when the shell is completely closed – other than drilling through. One creature who is good at opening them are starfish. Seabirds are known to drop these on roads and buildings trying to crack them open. But for the most part, it is a pretty good defense.
Bivalves possess two siphons, one drawing water in, the other expelling it, and use this not only for breathing but for collecting food – all bivalves are filter feeders. They will, at times, inhale sand particles that they cannot expel. The tend to secrete nacre (mother of pearl – shell material) over these sand grains forming pearls. Most of these are not round and are of little value to humans. But occasionally…
The pen clam is a common bivalve found in grassbeds.
Photo: Victoria College.
Oysters may be one of the more famous of the bivalves, but they are not as common in seagrass beds as other species. Most of our seagrass species require higher salinities which support both oyster predators and disease, thus we do not see as many in the grasses. Clams are different. They do quite well here, though we do not see them often because they bury within the substrate. We more often see the remaining shells after they have been consumed, or otherwise died. The southern quahog, pen shell, and razor clam are clams common to our grassbeds.
The one group sought after are the bay scallops. Scallops differ from their bivalve cousins in that they have small blue eyes at the end of each ridge on the shell that can detect predators and have the ability to swim to get away. They usually sit on top of the grasses and require them for their young (spat) to settle out. They are a very popular recreational fishery in the Big Bend area where thousands come very year to get their quota of this sweet tasting seafood product.
Bay Scallop.
Photo: FWC
There is another group of mollusk that are – at times – encountered in the seagrass beds… the cephalopods. These are mollusk that have lost their external calcium carbonate shells and use other means to defend themselves. This includes speed (they are very fast), color change (they have cells called chromatophores that allow them to do this), literally changing the texture of their skin to look and feel like the environment they are in at the moment, and expelling ink like some of the slugs. This includes the octopus and squid. Both are more active at night but have been seen during daylight hours.
The chromatophores allow the cephalopods to change colors and patterns to blend in.
Photo: California Sea Grant
As mentioned, shell collecting is very popular and finding mollusk shells in the grassbeds is something many explorers get excited about. You should understand that taking a shell with a living organism still within is not good. Some areas, including state parks, do not allow the removal of empty ones either. You should check before removing.
The open grasslands of the American west support huge herds of grazing herbivores such as bison, antelope, and deer. These large herds again support populations of hunters such as wolves, coyotes, and – historically – bears. The huge acres of wetland grasses we call marshes are productive as well, with all sorts of grazing creatures that feed on the grass like snails and insects, which in turn support populations of first order carnivores like birds, crabs, and turtles, who then feed larger predators like alligators, otters, and raccoons.
The salt marsh is full of life, if you look close enough. Photo: Rick O’Connor
One would think that the submerged seagrass meadows would work in the same way. But there are no large herds of bison like creatures that graze on the grasses. True, manatees and sea turtles do graze on these, but not in the numbers we see with bison and antelope. There are numerous species of snails and crustaceans that live in seagrass, but it is not the grass they are interested in… it is the epibiota. These epibiota are the key to vast diversity of creatures living in seagrasses. If you snorkel or seine through a submerged grassbed you will notice the majority of creatures are small. This place is a nursery for the estuarine and marine environments. These grasses provide excellent hiding places and the epibiota provide the food they need to grow.
Grassbeds are also full of life, albeit small creatures.
Photo: Virginia Sea Grant
So, what are these epibiota?
The term epibiota means “creatures that live on other creatures”. They can be further broken down into epiphytes (plants that growth on other creatures), and epizoids (animals that grow on other creatures). Spanish moss is a familiar example of an epiphyte most people know. Barnacles growing on a turtle shell, or a whale could be an epizoid you are familiar with. Many epibiota are small, even microscopic. You can see the algae growing on the shells of turtles, or the fur of the sloth. There are also numerous epizoids that are microscopic, and no one sees. It is a whole field of microbiology – the study of the natural history and diversity of this tiny world that, certainly in the case of seagrasses, makes the whole thing work.
The wide blades of turtle grass provide habitat for a variety of epibiota.
Photo: UF IFAS
With the seagrasses you will not always see the epibiota we are talking about. At times, there are mats of algae growing on the grass like Spanish moss on oak trees. We typically see these epibiotic macroalgae growing on seagrasses in the spring and summer. Most of these algal mats are red algae. Studies have shown that they support juvenile animals as hiding habitat and can increase the overall biomass of seagrass meadows. But, like with all things, too much of a good thing can have a negative effect on seagrass meadows as well. The seaweed can smother the grasses, reducing needed sunlight, and enhance the decline of seagrasses in some areas.
Gracilaria is a common epiphytic red algae growing in our seagrass beds. Photo: Rick O’Connor
Most of the epibiota feeding the growing populations of shellfish and finfish using these nurseries are microscopic plants and animals that appear to us as “scum” on the blades of the grass. As you might expect, the wider the blade (in this case turtle grass) can support a higher diversity and abundance of growing grazers than the thinner shoal grass.
A study conducted in 1964 listed 113 species of microscopic algae existing on the blades of seagrasses in Florida. They include such creatures as diatoms, cynobacteria, and bryozoans. We will focus on these.
Diatoms are quite abundant on seagrass blades and provide for microscopic grazers.
Photo: University of New Hampshire
Diatoms are single celled plant-like algae that are encased in a clear silica shell. They are one of the most abundant forms of oxygen producing plant-like creatures found in the sea. Many species drift with the phytoplankton layers of the open ocean. Others are benthic, living on the bottom upon rocks, seawalls, turtle shells, and seagrasses. It has been stated that 50% of the oxygen produced on our plant comes from the diatoms and the dinoflagellates (another microscopic plankton).
Cells of a species of cyanobacteria.
Photo: Florida Atlantic University.
Cyanobacteria are what many call blue-green algae. They produce a darker colored green with their photosynthetic pigments – thus the name blue-green algae – but were not initially identified as a bacteria – which they are now because they lack an organized nucleus. Many have heard of the recent cyanobacteria blooms in central and south Florida in freshwater systems. Some species are toxic and have caused fish kills and even made pets, who drank from water with cynaobacteria, very sick. There hundreds of different species found in marine systems. Like diatoms, some live in the water column, others are attached to an object on the bottom – like seagrasses.
This beautiful matrix was built by a group of microscopic animals known as bryozoans.
Bryozoans are microscopic colonial animals. They act and behave similar to corals, though they are much smaller. Some species appear as a “cast net” over the shell of a snail or clam, and can be seen on blades of turtle grass as well. There are many other species of these colonial creatures that call seagrass home.
We are highlighting these three groups but there are many other forms of epiphytes and epizoids growing on these grass blades. And it is these that the small grazers, like tiny crustaceans, feed upon, which in turn are what the millions of small silver juvenile finfish and crabs are feeding on. The seagrass meadow biodiversity and productivity is dependent on them and most Panhandle folks do not know they are there. Dr. Edward O. Wilson made a comment in his book Half Earth, that we have been focused on conservation of wildlife and habitat for many years now – but we fully do not understand what it is we are trying to conserve. We focus on blue crab and manatee conservation and do not realize that conservation of these micro-communities is essential for conservation, or restoration, success. The first step in conserving such communities is knowing they exist and how they support the system. You now have a little more knowledge of them, but there is SO much more to learn.
Many in the Florida panhandle are aware of the importance of seagrasses to estuarine ecology. They have heard this many times before and have heard how important it is to protect them. Some are aware that they are important as a nursery for many commercial important fin and shellfish. But fewer are aware of the diversity of life that exists in these “fields of grass”. Much of the life there is small and unnoticeable until you don a mask and explore. Even then, you need to slow down and look closely.
In this series on “Sea of Grass” we will be looking at some of the species that reside in these massive meadows expanding the Florida panhandle. We begin with the grasses themselves.
Seagrasses are just that – grasses that grow “under the sea”. They are similar in many ways to the grasses that grow in your yards. Their blades extend above the sediment and are usually all one sees as they are exploring the meadows. Being true plants, they do have stems – but these stems run horizontally beneath the sediments and are called rhizomes. Rhizomes are like “runners” and extend the plants across the landscape. Many have discovered rhizomes in their yards when pulling weeds. You begin to pull and a the runner exposes itself like pulling a thread from a sweater. From these rhizomes extend the small roots. Like lawn grass, seagrass use the roots to help anchor them in place and remove water and nutrients from the environment. But they are immersed in water and, like many marine creatures, have the ability to desalinate it so they have a source of freshwater.
Like all plants, seagrasses require sunlight for photosynthesis. Thus, they must grow in shallow water. In the western panhandle they are limited by the availability of light and are usually found in the estuaries where the water depth is not more than 10 feet. As you move into the eastern panhandle, particularly close to where the Big Bend begins, there are fewer large rivers depositing muddy water, more expanses of salt marsh to remove sediments from runoff, here seagrasses can grow deeper. Here they can expand into the open Gulf of Mexico itself producing hundreds of thousands of acres of these grass meadows.
Seagrass beds have declined over the last half century.
Photo: Rick O’Connor
They are not fond of high energy systems. Large waves can rip seagrasses from the bottom and deposit them onshore. In the western panhandle the Gulf generates larger waves and thus the grasses are found in the protection of the lagoons, sounds, and bayous. Near the Big Bend natural wave energy is low enough to support them in the open Gulf. It has been estimated that Florida has between 2.2 and 2.5 million acres of seagrass. Most of this is along the west coast of the peninsula running from the Florida Keys to the Big Bend1.
There are seven known species of seagrass in the state. Three of these are common in the panhandle and an additional one, Manatee grass (Syringodium filiforme), is beginning to expand its range into our area.
An amazing meadow of turtle grass.
Photo: Virginia Sea Grant
Two of our common species prefer more saline water – water with a salinity at least 20 parts per thousand (ppt). Those are Turtle grass (Thalassia testudinum) and Shoal grass (Halodule wrightii). These grasses both have flat blades but differ in blade width. Turtle grass is wider (4-12mm) and resembles St. Augustine grass from our lawns. Because of the wider blade, they grow in deeper water (not being able to tolerate the break waves and whitecaps near the surface). Shoal grass is very thin (<4mm) and feels more like human hair when you run your toes and fingers through it. Manatee grass resembles shoal grass in size but has a round blade instead of a flat one. In the Pensacola area we are beginning to find patches of it growing in Big Lagoon and Santa Rosa Sound.
Shoal Grass
Photo: Florida Department of Environmental Protection
Widgeon grass (Ruppia martimia) can tolerate the higher salinities of the lower estuary but can also tolerate the lower salinities of the upper estuary. It dominates the lagoons and bayous of the upper Pensacola Bay system. It has a thin flat blade like shoal grass but differs in that it branches as it grows instead of a single blade extending about the surface.
Widgeon Grass
These meadows of seagrass provide food and habitat for a myriad of marine creatures, who we will meet in other posts in this series. In Part 2 we will begin with one that is very important but very few know is even there – the epiphytes.
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.
