We are fortunate to have several whale species that have been spotted in the Gulf of Mexico including humpback whales, Rice whales, fin whales, sperm whales, sei whales, and orca whales. Recently, however, we have seen multiple reports of whale sharks near shore in Destin and Panama City Beach.
Whale sharks, however, are not whales, but the largest shark species and the largest fish alive today. Whale sharks aren’t even closely related to whales. They have gills, not blow holes. They are huge, up to 46 feet in length and weigh up to 22,000 lbs., the weight of two African elephants. Despite their large size, they are filter feeders with plankton being their main food, although they are also known to eat squid, krill, and small baitfish. They glide through the water at speeds of less than 3 m/hr, gently swinging their bodies side to side. They are not aggressive and pose no threats to humans.
Whale sharks prefer warm water, which is why they can be found in tropical areas and are often attracted to coastal areas due to a higher abundance of food. It’s no surprise, then, that they have been spotted in the Gulf. June to October is whale shark season in the Gulf, with Destin sightings being reported previously in 2013 and 2020. They are also found in many other countries around the world including Mozambique, Philippines, Honduras, Ecuador, Australia, Belize, Thailand, Egypt, Mexico, Seychelles, and the Maldives.
Unsurprisingly, many ocean lovers are desperate to get a glimpse of these majestic creatures in the water. However, experts recommend a hands-off policy for these gentle sea creatures. The Okaloosa Coastal Resource Team has been collaborating with NOAA scientists at the University of Southern Mississippi to tag 10 of this year’s visitors to gain valuable insights into their migratory patterns and habitat use. You can follow their Facebook page for updates on current locations and tracking data. https://www.facebook.com/whalesharkresearch
With this article we are going to begin a short series on the biogeography of panhandle vertebrates. Biogeography is the study of distribution of life and why species are found where they are. Many are interested in what species are found in a specific location, such as which sharks are found in our area, but understanding why others are not is as interesting.
The Bull Shark is considered one of the more dangerous sharks in the Gulf. This fish can enter freshwater but rarely swims far upstream. Photo: Florida Sea Grant
All species have a point of origin and from there they disperse across the landscape, or ocean, until they reach a barrier that stops that dispersal. These barriers can be something physical, like a mountain range, something climatic, like the average temperature, or something biological, like to abundance of a specific food or predator. There are a lot of barriers that impede dispersal and explain why some species are not present in some locations.
Sharks are marine fish. In general, there is little to impede the dispersal of marine fish. All oceans are connected and there is no reason why a shark found in the Gulf of Mexico could not swim to Australia, and some have. But there are barriers that keep some species of south Florida fish from reaching north Florida – mean water temperature being one.
There are 24 species of sharks from nine different families found in the Gulf of Mexico. Most have a wide distribution range, and some are found worldwide. Nurse sharks are more tropical, common in the Keys, but are found in our area of the northern Gulf of Mexico. They are fans of structure and are often found near our artificial reefs.
Whale sharks and hammerheads are circumtropical, meaning they are restricted by water temperature but found worldwide in warmer waters. Whale sharks are the largest of all fish, reaching a mean length of 45 feet, and are not common near shore. They are plankton feeders and, though large, are harmless to humans. There are five species of hammerheads found in the Gulf of Mexico. They are easily identified by their “hammer” shaped head and are known for their large dorsal fin that, at times, will extend above the surface while they are swimming. Finding species of hammerhead inside the bay is not uncommon.
Several of our local sharks are not as restricted by water temperature and are found as far north as Canada. Sand tigers, threshers, and dogfish seem to prefer the cooler waters and, though found in the Gulf, are not common. There are two members of the mackerel shark family found here. Great whites, of movie fame, prefer cooler waters and are found worldwide – except for polar waters. There are records in the Gulf, but most are offshore in cooler waters. As you know, these are large predatory sharks, reaching up to 25 feet in length, and are known to feed on large prey such as seals. Their cousin the shortfin mako, prefers warmer waters and is more common here. Nearshore encounters with makos is rare but has happened.
The largest family, and best known, are the requiem sharks. There are 13 species in the Gulf, and many are common in our area. Many are not as restricted by water temperature and can be found as far north as New York. Bull sharks are not restricted by salinity and have been found up rivers in Alabama, and Louisiana. Silky sharks are more tropical, and the tiger and spinner sharks are more circumtropical.
The geographic distribution of sharks seems centered on water temperature. Most can easily swim the oceans to locations across the globe but congregate in areas of preferred temperatures and food. Though feared because of attacks on humans, a rare thing actually, they are fascinating animals and world travelers.
This group not only provides research data to NOAA, but are also stewards of pier etiquette, Navarre Beach and the surrounding area. Tourists and locals alike are treated to stories of local history, fish tales and general information about the area from Earnie and Team True Blue members. In addition, visitors may see a shark tagged and released or the group catching large fish to be used for shark bait
Photo Credit Earnie Polk
The NOAA Cooperative Shark Tagging program has been in existence since 1962. Today thousands of anglers along the Gulf of Mexico and Atlantic Coast have tagged more than 295,000 sharks representing 52 different species. More than 17,500 sharks have been recaptured! This program provides information on shark migration patterns, numbers, locations, migrations, age and growth rates, behavior and mortality.
Earnie estimates he has tagged more than one-thousand sharks for the program. He has refined handling methods to have the least impact on the animal to ensure the survival of the shark after release. The team brings the shark to shore to measure the length and tag the shark just behind the dorsal fin.
Earnie shared an interesting story about tagging at least eighty Dusky sharks during a red tide event during the late fall of 2015. He noticed as the north winds blew the red tide out, an open area was created along the coast. This allowed clear water for the sharks to travel closer to shore and within distance of the tag and release team.
Today, the tiger shark is the most common shark the team tags and releases. Recently, the team tagged and released a 12’6” tiger shark. Randy Meredith, of the Navarre Newspaper agreed to share the video he edited of the Navarre Fishing Pier and the tag and release of the tiger shark in February 2021.
The team uses heavy gear, 200-pound test line and Everol reels that have drag pressure for a shorter fight to reduce stress on the animal for a better survival rate. Gear is spread along the rails at the end of the pier. Baited lines range from approximately 75 to 400 yards off the end of the pier. You probably wonder how they get their line 400 yards off the pier. Earnie has modified a fiberglass kayak with a battery powered motor. It is lowered to the surface of the water; team members drop their lines onto the kayak and Earnie pilots the kayak out to deeper water.
Their strategy is that by dropping more lines, at different depths and locations a shark is bound to trip over one of the lines. They use bait they catch on the pier or other fishing trips. Something big had hit on a cow nose ray over the weekend, so most members were using rays for bait. One team member said, “if the fish had hit on a watermelon, we all would be using watermelon for bait.” These guys have a great sense of humor!!
Make sure that the next time you visit Navarre Beach, you take time to walk out to the end of the fishing pier to learn about local sharks, history and the area from these interesting, funny and helpful anglers. On clear days you may see sharks, rays, sea turtles and other types of marine life as you venture out.
Be sure to stop at the pier store to pay the $1.00 per-person fee to enjoy the view!
This is not a word that most visitors to the beach want to hear. However, shark attacks are actually not that common and the risk is very low. People hear this every year on shark programs, but it does not seem to make them feel any better. Here is what the International Shark Attack File says (as of 2020)…
–Since the year 1580 there have been 3164 unprovoked shark attacks around the world.
Let that sink in for a moment… 3000 unprovoked attacks on humans in the last 440 years.
Now consider the number of car accident victims that have occurred in the last month within the United States. See what they are getting at? Let’s look at more…
–Of the 3164 reported unprovoked attacks (yes… these data only include what was reported) 1483 were from the United States… 47% of them. This may be due to the fact we are “water people”. The other top countries are Australia, South Africa, and Brazil, all “water people” as well.
–Of the 3164 reports 851 were from Florida (27%). This is the number of reported shark attacks in our state since the Spanish settled it. This comes out to 2 each year – though the data shows a sharp increase in attacks starting in the 1970s (most have occurred since then).
–Of the 3164 reports 25 were from the panhandle region (0.8%) and 7 from the Pensacola Bay area (0.2%).
Let that sink in for a moment. Seven reported attacks from the Pensacola Beach area since the time DeLuna landed here in 1559… 7.
And lets once again consider the number of vehicle accidents that will occur in the bay area today.
These numbers have been posted before. Yet people are still very worried when the hear sharks are in the Pensacola Beach region. When attacks occur, they are big news. The International Shark Attack File does give trends and suggestions on what to do. But as many say, sharks are the least of your worries when you are planning a day at the beach.
Now that we have said all of that, they are truly amazing animals.
They are fish but differ in that their skeletons lack hard calcified bone – they are cartilaginous. There are 25 species in 9 different families in the Gulf of Mexico. Many are completely harmless – 13 of the 25 have been reported to have had unprovoked attacks somewhere around the world – the white, tiger, and bull sharks leading the way. Several rarely come close to shore.
Sharks lack a swim bladder and thus cannot “float” in the water column the way your aquarium fish do. Some, like the nurse and angel sharks, rest on the bottom. Others, like the white and blue sharks, swim constantly to get water flowing over their gills.
Because of this, they are very streamlined with reduce scales. They actually have modified teeth for scales – called placoid scales. Their fins are angular and rigid (as are other open water fish) and some can swim quite fast – makos have been clocked at over 30 mph for short distances. Many have seen video of large white sharks exploding with a burst of speed on a sea lion and actually leaping out of the water with it.
Many species do lay eggs, but others keep the eggs within and give live birth after they hatch. One species, the sand tiger, produce four embryos within the mother. The first to hatch consumes the other three!
The teeth of sharks are famous. Rows of them, some pointed, some are serrated, all are designed to cut and swallow. The tiger shark has a serrated tooth that is angled like a can opener. They can use this to “open” sea turtle shells – adding them to their rather large menu. They “shed” these frequently – placing a new sharp tooth where the dull old one was – and will go through tens of thousands of teeth in a lifetime.
The sensory system is one of the most amazing in the world. Tiny gelatinous cells along their sides, called the lateral line, detect pressure waves from great distances. Splashing, thrashing movements made by fish can be detected a mile away – and get their attention. As they approach the sound their sense of smell kicks in. It has been said that a shark can detect one drop of blood in thousands of gallons of water – and it is true. However, the sharks must be down current of the victim to detect it. Their eyes are much better than most think. They have “crystals” within their retina that act as mirrors reflecting light that enters. Imagine turning on a flashlight in a dark room. Now imagine doing this if the walls and ceiling were mirrors – you kind of understand how they can actually see pretty well even in the low light. That said, light does not travel well under water, so they rely on their other senses more. And as if that were not enough. They have small gelatinous cells around the head region that can detect small electric fields. When a shark bites, it must close its eyes and – as the fishermen say – “roll back” out of the head. At this point the shark is basically blind and cannot see the target it is trying to bite. However, if you move out of the way, the weak electric fields produced by your muscles in doing so can be detected by these cells and the shark knows where you are.
Cool – and scary at the same time. Let’s meet a few of these amazing fish in our area.
The nurse shark. Notice the barbels (whiskers) on its head. Photo: NOAA
This is one of the bottom dwelling sharks that appear harmless – and they are – but if provoked, they will bite. They have less angular fins, or a brownish-bronze color, and really like structure – they are found on our reefs. They posses a “whisker-like” structure called a barbel. These are common on other bottom fish, like catfish, and possess chemo-sensory cells to detect prey buried in the sand. They are not as common here as they are in the Keys, but they have been seen. They can reach lengths of 14 feet.
Blacktip sharks are one of the smaller sharks in our area reaching a length of 59 inches. They are known to leap from the water. Photo: Florida Sea Grant
Blacktip – Spinner
These are grouped together because (a) they resemble each other, and (b) they are both common here.
They are both stream-lined in shape and have blacktips on their fins. Actually, spinner sharks have more fins tipped-black than the blacktip. The anal fin of the spinner is tipped black, but this is not the case for the blacktip. The spinner gets its name from the habit of leaping from the water and spinning very fast as it does so. Both are quite common in the Gulf and the bay. They reach about eight feet in length and unprovoked attacks are very rare.
The Scalloped Hammerhead is one of five species of hammerheads in the Gulf. It is commonly found in the bays. Photo: Florida Sea Grant
This is a creepy group – check out the head. It is one that many people fear, and unprovoked attacks have occurred. The reader may not know that there are more than one kind – five species actually. They have a tall dorsal fin which sometimes extends above the water when swimming near the surface – the classic “shark is coming” look. Their heads are aerofoil shaped and there are several possible explanations for this. 1) It is more aerodynamic, making it easier for this ram-jetter to swim, using less energy to do so. 2) It is a battery of sensory cells. By swinging the head back and forth, as they do, it is an advanced radar searching for prey, possibly finding it before other sharks do. There are stories of hammerheads arriving first. 3) It is also believed they use their electric sense to detect buried prey – the shape making this easier to find and expose them. It could very well be that all of these could explain the shape.
This pregnant bull shark has an impressive girth.
Since the film Jaws the world has turned its attention from solely the white shark – to the bull shark. As you can imagine, it is hard for a shark attack victim to tell you which species bit them – “I don’t know… it was a big gray thing chomping on my leg!” or “It was a great white!” because that is the only one many know. But studies sine the 1970s suggest that the bull shark is an aggressive species and may be responsible for a lot of attacks. Particularly in the estuaries and upper estuaries. Bull sharks are what we call euryhaline – they have tolerance for a wide range of salinities. This shark has been reported in low salinities of the upper estuaries and even into freshwater rivers. One report had them over 100 miles from the coast – they are certainly where the people are.
The extremely long upper lobe of the thresher shark. Image: NOAA
These are bizarre looking sharks. Most sharks have what we call a heterocercal tail – different – different meaning the upper lobe of the forked tail is longer than the lower. But the threshers take this to the extreme – the tail can make up almost half of their body length, which can be 20 feet. It is believed that use this extremely long tail to herd and stun baitfish – their favorite prey. They prefer colder waters and records in the Gulf are not common. Those that exist suggest they live offshore and are rarely encountered near beaches. There are no unprovoked attacks reported from this shark.
The massive whale shark. Photo: Florida Museum of Natural History.
Amazing… heart stopping… what else can you say. Encounters with the largest fish on our planet are rare – but when they do happen you will never forget it – it will be one of the highlights of your life. As the name suggest – these are large sharks, with a mean length of 45 feet but some reporting in at 60 feet. They are easily recognized first by their size, but also their coloration. They are brownish color with beige or white spots in nice rows running across the dorsal side. They swim slowly filtering plankton from the sea – though will occasionally take in a fish. Some reports show them vertical in the water column moving up and down filtering from a school of plankton or tiny fish. They are rarely seen because they tend to dive deeper during the day with the plankton layer – then surfacing at night following the same plankton. They are, unfortunately, sometimes struck by boats while at the surface.
When one thinks of the Emerald Coast, visions of sparkling water, baby-powder beaches, rental houses and high-rises interwoven with seafood and pizza restaurants appear. The coast is dotted with fishing boats, pirate ships and dolphin cruises and the beaches are littered with people. But it is what glides under the water that some people are curious about. “Are there sharks in the water here?” is a question I often get from locals and tourists alike. The answer is yes, sharks call saltwater home.
Sharks evoke a variety of emotions in people. Some folks are fascinated and list shark fishing and diving with a shark on their bucket lists. Others are terrified, convinced that sharks only exist to hunt them and bite them while they take a swim. Unfortunately for the sharks, their appearance plays into this later fear, with sharp teeth, unblinking eyes and sleek bodies. The reality is that most sharks only grow up to three feet in length and eat small shrimp, crabs and shrimp, not humans. But it is true that bull, tiger and great white sharks are all large species that have been known to attack humans.
Of the 540 different species of sharks in the world, there are about twelve that call the Emerald Coast home including Atlantic sharpnose, bonnet head, blacktip, bull, dusky, great white, hammerhead, nurse, mako, sand, spinner, and tiger. They don’t all stick around all year, with some migrating south in the winter, while others migrate north.
Sharks use their seven senses to interpret their environment: smell, sight, sound, pressure, touch, electroreception, and taste. Most shark attacks occur when a human is mistakenly identified as prey. There are some easy measures you can take to reduce the risk.
Swim with others, this may intimidate sharks and allows someone to go for help if a bite occurs.
Remove jewelry as it can look like an attractive shiny fish underwater.
Don’t swim where folks are fishing as bait in the water may attract sharks.
Pay attention to any schools of baitfish in the area that may be attracting sharks.
Do not swim at dusk or dawn when visibility may be poor.
Learn how to identify various shark species
Remember, shark attacks on humans are rare. Reports of stepping on stingrays, jellyfish stings, lightning, dangerous surf conditions and car accidents greatly outnumber the number of shark attacks every year.
The recent attacks on swimmers in North Carolina have once again brought up the topic of sharks. And of course, “Shark Week” is coming up. It is understandable why people are concerned about swimming in waters were animals weighing several hundred pounds with rows of sharp, sometimes serrated, teeth are lurking. It is also understandable that local tourism groups are concerned that visitors are concerned. Sounds like the movie Jaws all over again.
The Bull Shark is considered one of the more dangerous sharks in the Gulf. This fish can enter freshwater but rarely swims far upstream. Photo: Florida Sea Grant
So, what is the risk?
It is good question to ask for anything we feel uncomfortable with. Hiking in Rockies where bears might roam. Hiking in wetlands of Florida or deserts of the American southwest where venomous snakes may lurk. Paddling the creeks and rivers of the American southeast where alligators could be basking. All are concerns.
According to G. Tyler Miller and Scott E. Spoolman, a risk is the probability of suffering harm from a hazard that can cause injury, disease, death, economic loss, or damage. There is a difference between possibility and probability. There is always the possibility of a shark attack, but what is the probability it will happen? Unfortunately, media blast can create a scare over a highly unlikely possibility without discussing the data driven probability of it happening. We all take risk every day – riding in a car, smoking, drinking alcohol, eating bad food – which can lead to heart issues and the number one killer of humans worldwide, and more. Many of these we do not consider risky. We feel we are in control, understand the risk, and are managing from them. Those risk we have little control over – shark attacks – seem more of a risk than they really are. The car is far more dangerous, yet we do not hesitate to get in one at zoom onto the interstate.
Let’s conduct a simple risk assessment of shark attacks…
What is the hazard of concern?
Being attacked by a shark
Dying from the shark attack
How likely is the event?
The International Shark Attack File was first developed after World War II to address the issue of shark attacks on US Navy personnel, but expended to everyone. It was originally housed at the Smithsonian Institute but is currently housed at the Florida Museum of Natural History in Gainesville. Based on their records of unprovoked shark attacks (the ones we are truly interested in) there have been 3103 attacks on humans since 1580. 46% of those were in the United States, ranking us #1. Number two and three are Australia and South Africa. So as far as nations go, we are number one for attacks. However, this equates to 7 attacks / year – worldwide. And not all of those died. Most did not.
Since 1837, 828 attacks (57%) occurred in Florida. This equates to 4.5 attacks / year. Florida is number one, followed by Hawaii and California.
What about counties in Florida?
Since 1882 there have been 303 attacks (36%) in Volusia County. This equates to 2.2 attacks/year. The total number of attacks in Florida panhandle counties since 1882 have been 25 – this is 0.2 attacks/year for the entire panhandle.
What were these Floridians and visitors doing when they were attacked?
Surface recreation (surfing, boogie boarding), swimming, and wading top the list, the other activities were logged.
So, there have between 8-10 shark attacks each year, and two fatalities, worldwide.
The white shark is responsible for more attacks on humans than any other species. It is found in the Gulf of Mexico in the winter months but there are no reports of attacks in Florida. Photo courtesy of UF IFAS
The Risk Assessment is used to develop a Risk Management Plan
First, How do these shark attack data compare with other risks?
I wondered how many car accidents occur each year worldwide?
According to USA Insurance Coverage, who got their data from the National Highway Traffic Administration – 5,250,000 each year in the United States alone. About one every 60 seconds.
Situations that cause human deaths annually in the United States
Heart disease 652,486 1 in 5 people
Cancer 553,888 1 in 7
Stroke 150,074 1 in 24
Shark attack1 1 in 3,748,067
Between 1992-2000 there were 2 shark attacks in Florida. In that same time period, there were 135 drownings.
Between 2004 and 2013, 361 people drowned in rip currents. During that same period, 8 people were attacked by sharks.
Between 1990 and 2009, in Florida, 112,581 people were involved in bicycle accidents; 2272 died. In that same period, there were 435 shark attacks in Florida; 4 died.
And my favorite…
Between 1984 and 1987, 6339 people had to visit a hospital in New York City because they were bitten by a human. This was 1585 / year. In that same period there were 45 shark attacks in the entire United States. This was 11 / year.
Second, How should we reduce the risk of shark attack?
Well… as you can see from the assessment and comparative risk analysis, many would say you did not need to develop a plan to reduce risk because the risk is too low to fool with. You should spend time on hazards that are of a more real concern. That said, there are some things you can do.
– Avoid excessive splashing; it is known that sharks are attracted to this. It is also known that more often than not, they move away when they detect the source of the splashing.
– Avoid swimming when bleeding or in water with strong smells (like fish bait); this too will attract them.
– Most unprovoked attacks occur between 11:00 AM and 3:00 PM. But honestly, that is when most people are in the water. This could be different if most of us swim after sunset. That said, we recommend that you reduce swimming at dawn and dusk.
I hope this clear up some of the concerns about shark attacks. Yes, they do happen – but infrequently. There are some things you can do to reduce your risk, but these should not keep you from enjoying water related activities. Enjoy your time here on the Gulf coast. Be careful driving and try to eat healthier.