Mountains of Jellyfish

Mountains of Jellyfish

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. 

The Science of Sharks

The Science of Sharks

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.  

For more information: https://www.floridamuseum.ufl.edu/sharks/education-resources/ 

A bull shark being tagged by researchers (credit: Florida Sea Grant).

An Equal Opportunity Institution” 

Outdoor Ethics

Outdoor Ethics

Baby terns on Pensacola Beach are camouflaged in plain sight on the sand. This coloration protects them from predators but can also make them vulnerable to people walking through nesting areas. Photo credit: UF IFAS Extension

The controversial incident recently in New York between a birdwatcher and a dog owner got me thinking about outdoor ethics. Most of us are familiar with the “leave no trace” principles of “taking only photographs and leaving only footprints.” This concept is vital to keeping our natural places beautiful, clean, and safe. However, there are several other matters of ethics and courtesy one should consider when spending time outdoors.

  1. On our Gulf beaches in the summer, sea turtles and shorebirds are nesting. The presence of this type of wildlife is an integral part of why people want to visit our shores—to see animals they can’t see at home, and to know there’s a place in the world where this natural beauty exists. Bird and turtle eggs are fragile, and the newly hatched young are extremely vulnerable. Signage is up all over, so please observe speed limits, avoid marked nesting areas, and don’t feed or chase birds. Flying away from a perceived predator expends unnecessary energy that birds need to care for young, find food, and avoid other threats.

    When on a multi-use trail, it is important to use common courtesy to prevent accidents. Photo credit: Carrie Stevenson, UF IFAS Extension

  2. On a trail, the rules of thumb are these: hikers yield to equestrians, cyclists yield to all other users, and anyone on a trail should announce themselves when passing another person from behind.
  3. Obey leash laws, and keep your leash short when approaching someone else to prevent unwanted encounters between pets, wildlife, or other people. Keep in mind that some dogs frighten easily and respond aggressively regardless of how well-trained your dog is. In addition, young children or adults with physical limitations can be knocked down by an overly friendly pet.
  4. Keep plenty of space between your group and others when visiting parks and beaches. This not only abides by current health recommendations, but also allows for privacy, quiet, and avoidance of physically disturbing others with a stray ball or Frisbee.

Summer is beautiful in northwest Florida, and we welcome visitors from all over the world. Common courtesy will help make everyone’s experience enjoyable.

The Thing About Sharks

The Thing About Sharks

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.

 

Which state?

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 attack      1                           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.

 

References

 

International Shark Attack File.  https://www.floridamuseum.ufl.edu/shark-attacks/.

 

Miller, G.T., S.E. Spoolman. 2011. Living in the Environment. 16th Edition.  Brooks and Cole, Cengage Learning.  Belmont CA. pp. 121.

 

USA Insurance. https://www.usacoverage.com/auto-insurance/how-many-driving-accidents-occur-each-year.html.

Strategies for Avoiding Seasickness

Strategies for Avoiding Seasickness

Boats at dock in harbor

Boats at a calm rest in Massalina Bayou, Bay County, Florida.

Wow! I was so excited to hear the news. Dad had just called to invite me on a deep sea trip out of Galveston. I had grown up fishing but had never been to sea. My mind raced – surely the fish would be bigger than any bass or catfish we ever caught. I day dreamed for a few moments of being in the newspaper with the headline, “Local Teen Catches World Record Red Snapper”.

It seemed more like a Christmas Morning when dad woke me up for our 100-mile car trip to the coast. We hurried to breakfast just a few hours before sunrise. I had the best fluffy pancakes with a lot of syrup, washed down with coffee with extra cream and sugar. I was wide awake and ready for the fishing adventure of a lifetime!

The crew welcomed us all aboard and helped us settle in. Dad was still tired and went to nap below deck. I was outside taking in all the sights of a busy head boat, including the smell of diesel fuel, bait, and dressed fish. About an hour into my great fishing adventure things started to change. I grew queasy and tired. I went to find my dad and he was already sick. I looked at him and then turned around to go out the ship’s door. My eyes saw the horizon twist sideways and my brain said “WRONG!!!” – this was my first encounter with seasickness.

The crew quickly moved both of us back outside. I was issued a pair of elastic pressure wristbands – the elastic holds a small ball into the underside of your wrist. The attention and sympathy might have made me feel a little better but there was really no recovery until we got back into the bay an excruciating 6 hours later. There were no headlines to write this day, only the chance to watch others catch fish while my stomach and head churned – often in opposite directions.

Fast forward to today, decades later. I often make trips into Gulf to help deploy artificial reefs without any problems with motion sickness. Some of my success in avoiding seasickness are lessons I learned from that dreadful introduction to deep sea fishing long ago.

  1. Be flexible with your schedule to maximize good weather and sea conditions. If you are susceptible to motion sickness in a car or plane this is an important indicator. Sticking to an exact time and date could set you up for a horrible experience. Charter companies want your repeat business and to enjoy the experience over and over again.
  2. Get plenty of rest before your fishing adventure. Come visit and if necessary spend the night. Start your day close to where you will be boarding the boat.
  3. Eat the right foods. You don’t need much food to start the day, keep it light and avoid fatty or sugary diet items. As the day goes by, eat snacks and lunch if you get hungry.
  4. Stay hydrated and in balance. Take in small sips when you are queasy or have thrown up. You need to drink but consuming several bottles of water in a short time period can create nausea.
  5. Avoid the smell zone. When possible, position yourself on the vessel to avoid intense odors like boat exhaust or fish waste in order to keep your stomach settled. It is best to stay away from other seasick individuals as their actions can influence your nausea.
  6. Mind over matter – Have confidence. Knowing you have prepared yourself to be on the water with sleep, diet, and hydration is often enough to avoid seasickness. However, if you routinely face motion or seasickness then a visit with your doctor can provide the best options to make your days at sea a blessing. Their help could be the final ingredient in your personal recipe for great times on the water with friends and family.

For more information, contact Scott Jackson at the UF/IFAS Extension Bay County Office at 850-784-6105.

After Shark Week; What Visitors Should Know About Sharks

After Shark Week; What Visitors Should Know About Sharks

In recent weeks, the country has heard about shark attacks off the Carolina coast and great whites off the northern coast of the Gulf of Mexico – then of course, we just completed “Shark Week”. This sometimes makes visitors to our beaches a bit unnerved about swimming.  Each year we hear about how other activities we engage in are much more dangerous than swimming in the Gulf where there are sharks – and this is true – but we may still have a concern in the back of our minds.  So – we will give you some information that will hopefully enlighten you on the issue of sharks.

 

First, what kind of sharks are in the Gulf and how common are they?

 

According to Dr. Hoese and Dr. Moore from Texas A&M, there are 30 species of sharks who have been found in the Gulf of Mexico – and this includes the great white. They range in size from the Cuban Dogfish (3 ft.) to the whale shark (60 ft. in length).  Each has their own niche.  Some, like the large whale sharks, are plankton feeders.  Others, like the blue and mako, are open ocean travelers covering large stretches of water hunting prey.  Others, like the blacktip and spinner, are more common near shore – close to estuary outfalls where food is plentiful.  And others still, like nurses sharks, are bottom dwellers feeding on slow fish and crustaceans.

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

As far as how common they are – I was involved in shark tagging in the early 1980’s and we tagged several species. Blacktips and spinner sharks were very common.  We also tagged a lot of bull and dusky sharks – though dusky sharks are declining.  Tiger sharks were not as common at the time.  It was believed this was due to an increase in shark rodeos in the 1970’s – which were popular during the “Jaws” films.  However, those events stopped for several years and recent shark events have once again captured tigers.  There are five species of hammerheads that were tagged – the scalloped and bonnethead were the most common.  White sharks and makos are in the Gulf but were never tagged.  It was believed they spent more time offshore (where we were not sampling).  Both species have been seen closer to shore in recent years, but there are no reports of any problems from this.  It is possible they have been doing this all along and were just undetected.  Blacknose, finetooth, and silky sharks were also frequently tagged.

 

People are probably not surprised to hear that sharks frequent the bays. Many of the species mentioned above do so.  The small (3 ft.) Atlantic sharpnose shark is one of the most common.  Sawfish were once common in the estuaries but have declined significantly across the region to do over harvesting in the early 20th century.  They are currently protected.

 

You have probably also read that bull sharks have been found in freshwater rivers – and this is the case. Some have been found several miles up river systems.

 

What type of prey do sharks prefer and how to do they select and hunt for them?

 

This, of course, varies from species to species. Plankton feeding whale sharks generally cruise slowly through the water column filtering small fish and crustaceans – the same as the great whales.  They do tend to feeding in deeper water during the day and closer to the surface at night.  They are following what is known as the Deep Scattering Layer. This is a large layer of zooplankton (animal plankton) that migrates each day – deeper (600 feet or so) during the daylight hours and closer to the surface in the evenings.

 

Bottom dwelling sharks feed on benthic creatures like flounder and crabs. Many have the ability to detect their prey buried beneath the sand using electric perception they have.

 

Many species of sharks are what we call “ram-jetters”. This means they do not have a pump system to pump water over their gills.  So, in order to breath, they must swim forward.  Swimming continuously requires a lot of energy.  Most of them are what we call opportunistic feeders – meaning they will grab what they can.  Stomach analysis of such sharks find primarily fish and squid, but other creatures have been found – such as birds and even other sharks.  The general rule here is seek prey that is “easy”.  If your objective in feeding were to obtain energy – it would not make since to chase prey that would require a lot of energy to catch.  Simple first, and take opportunities when you can.  It is the ram-jetter species that people are most concerned.  Swimming and taking opportunities.  However, evidence suggest that we are not a prey of choice, not good opportunities.  More on this in a minute.

 

Tiger sharks are interesting. It is in their stomachs we find such things as hubcaps, metal, and other sorts of garbage.  Because of their tooth design, they are also capable of eating sea turtles.

 

How often do shark attacks on humans actually occur and what were the people doing that may have enticed it to happen?

 

Records on human shark attacks are kept at the International Shark Attack File at the Florida Museum of Natural History in Gainesville, FL.  This data set only logs unprovoked attacks – those where the people were doing their thing and all of a sudden… Not those where humans were pulling them into their boats after fishing or grabbing their tails while diving.

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

Based on this data – there have been 3031 unprovoked shark attacks reported worldwide since 1580 A.D. This equates to seven attacks / year.  Granted… not all attacks are reported, particularly from the undeveloped regions of the world – and from early history, but it does give us something to look at.

 

Currently, we are averaging between 70 and 100 shark attacks worldwide and between 5-15 of these are fatal. Honestly, this is very low when compared to other activities in which humans participate.

 

Year Deaths from Other Deaths from Shark Attacks
1959 – 2010 Lightning strikes – 1970 26
2004 – 2013 Rip Currents – 361 8
2001 – 2013 Dog bites – 364 11
2000 – 2007 Hunting accidents – 441 7
2002 – 2013 (Florida only) Boating accidents – 782 2

 

As you can see… the risk is much lower.

 

It is true that most of the shark attacks worldwide are in the United States (46%) and that most in the U.S. are in Florida (56%). However, it is believed that this is due to the number of Americans (and Floridians) who enjoy water activities.  In Florida, most of the encounters have been on the east coast – 89% of them!  There have only been 65 attacks reported from the west coast – only 37 from the Florida panhandle – since 1580 A.D.  There have only been six reported from Escambia County and one from Santa Rosa in that time.

 

As far as what people were doing when a shark attack occurred – most were surfing, but swimming has increased in recent years. This is believed to be connected to the increase in the number of humans swimming.  The human population visiting beaches, particularly in the U.S., has increased significantly.  Most shark attacks occur in near shore waters – which would make sense… that is where we are.  Most are the “hit & run” version – meaning the shark hits the person and runs… not returning.  Based on Florida reports, it is believed most of these are blacktips, spinners, and blacknose sharks.  These rarely end in a fatality.  “Bump & Bite” – meaning the shark circles, bumps the person, and then bites, are not as common.  It is believed most of these are from great whites, tigers, and bull sharks.  The few fatalities that happen are usually from this form of encounter.

 

Summary

 

When assessing “risk” in an activity you have to consider “control”. This means that the more you are in control of the situation, the less risky the activity seems to be.  Most feel that in the water, the shark is in control – this increases our fear and risk concern.  However, as mentioned in this article, many of the other activities we are involved – where we think we are in control – are far more risker than swimming on the open Gulf of Mexico.

 

However, shark attacks do occur and there are a few things swimmers can do to reduce their risk.

  • Do not swim alone – all predators will try and isolate an individual from a group before they attack – much easier to attack an individual than a group
  • Do not swim near dusk or after dark – to increase their chance of hunting success, sharks are more actively hunting in low light conditions
  • Remove shiny objectives like jewelry – sunlight hitting metal objectives can appear to be baitfish to a shark
  • Avoid blood in the water – it is true they have an excellent sense of smell – small amounts of blood in the water can be detected as far away as 100 feet suggesting easy prey nearby. Avoid swimming near fishing activity where bait and fish blood may be discharged into the water

I have been swimming in the Gulf all of my life. It is too much fun to worry about a low risk encounter with a shark.  Follow the simple rules suggested by the ISAF and you should not have any problems.

 

Resources

 

The International Shark Attack File – https://www.floridamuseum.ufl.edu/shark-attacks/.

 

Hoese, H.D., R.H. Moore. 1977. Fishes of the Gulf of Mexico; Texas, Louisiana & Adjacent Waters. Texas A&M Press, College Station TX. pp. 327.