All About Sharks

Hello, Adventurers! Welcome back to the Coastal Expeditions blog! If this is your first time visiting our blog, we’re happy to have you here. We are all about nature, adventure, and making the most out of the beautiful outdoors of South Carolina. If you enjoy all things hiking, paddling, kayaking, and spending time outdoors, you’ve come to the right place! Here on the blog, we dive deep into different habitats, excursions, conservation efforts, and nature programs. Our site is filled with interactive maps, destination guides, and educational resources. Since the weather is incredibly warm, we want to help you get out there and take advantage of all that the Lowcountry has to offer! We offer guided tours of the beautiful Lowcountry by kayak, paddleboard, ferry, boat, and private charter. We also have hands-on workshops taught by highly-trained guides on wilderness skills, birding, identifying native plants, sustainability, and camping. Anything you want to learn about, we teach! If you haven’t already, we encourage you to take a look around our site to learn more about our offerings. In our last post, we talked all about dolphins, which are fascinating marine creatures that can be spotted right here in the Lowcountry! Today, we’ll be talking about some more of our aquatic friends– Sharks! Yes, they are our friends, despite the fear that typically surrounds them. If you are interested in learning more about sharks, stick around! Let’s get right into it.

 

Although it may be hard to believe, sharks are actually fish, not mammals. More specifically, they belong to a group of cartilaginous fish, which are fish with skeletons primarily composed of cartilage, which is a hard but flexible material. Since cartilage is much lighter than bone, sharks are able to stay afloat easily. Other fish in this group are rays, skates, and sawfish. The sharks we know today are classified within the group known as Selachimorpha, and are actually the sister group to rays. (You can read all about stingrays in one of our previous blogs!) Scientists believe that sharks have existed for over 400 million years– 200 million years before the dinosaurs! Because they are made up of cartilage rather than bone, sharks do not leave behind bony fossils like we have seen with dinosaurs and other mammals. Instead, scientists have learned about sharks from finding fossilized teeth, skin scales, and vertebrae. Based on these artifacts that have been found, more than 2,000 species of shark have been discovered. The earliest known shark is known as Elegestolepis and is thought to have existed around 420 million years ago. Fossil records show that the ancient sharks that existed 370 million years ago looked closest to the sharks we know today.

 

Today, there are more than 500 species of sharks. They can be found in all seas, and generally do not live in freshwater. However, the bull shark and river shark can be found in both seawater and freshwater. In South Carolina, 38 species of sharks can be found roaming the saltwater. Sharks dwell in all parts of the ocean marine environment– Some stay in the deep, while others hang out closer to the shore. The most common species of sharks in South Carolina waters are the Atlantic sharpnose, sandbar, bonnethead, blacktip, finetooth, scalloped hammerhead, nurse, lemon, tiger, sand tiger, and dusky sharks! Sometimes, bull, blacknose, and spinner sharks can be spotted, but not as often. Sharks tend to stay closer to the shore in the spring and summer, and retreat off shore in the fall and winter months. Sharks range in size, varying from smaller lengths like 7 feet in length to the size of the whale shark, the largest fish in the world, which can reach up to 40 feet in length! 

 

As mentioned previously, shark skeletons are made up mainly of cartilage and connective tissue. The skin of a shark is made up of dermal denticles, which are small, tooth- or scale-like structures made up of collagenous fibers that work as an outer skeleton. Most sharks have eight fins, but some have as little as four. These fins generally consist of a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin. Pectoral fins are used to lift and steer, while pelvic fins help keep the shark stabilized while it swims. Dorsal fins are the fins most people are familiar with, located on the top of the shark, or its back. These fins are generally seen when a shark is near the water’s surface. Some sharks have a first and second dorsal fin.  Like pelvic fins, dorsal fins help stabilize the shark while swimming. In some species of shark, these fins are not enough to keep them stable. This is where anal fins come in– These are located on the bottom, or ventral, part of the shark and provide additional stability. The caudal fin, also known as the tail fin, helps the shark propel itself through the water. The shape of the caudal fins can vary depending on the species. 

 

Like other fish, sharks have gills to aid in respiration. Gills are respiratory organs that extract dissolved oxygen from the water and excrete carbon dioxide. Most bony fishes have one gill slit on each side of their bodies, but sharks have five to seven gill slits on both sides. Unlike other fish, the gills of a shark are not covered. When water enters the shark’s mouth as it swims, the shark closes its mouth, forcing the water over its internal gills. Oxygen is extracted from the seawater and the water is expelled through the gill slits. 

 

Just like their close relatives, rays, the jaws of sharks are not attached to the cranium. They do not have a jawbone, so the teeth are embedded in the gums. The inside of a shark’s mouth is full of multiple rows of teeth, and they are constantly replaced through a shark’s life. In fact, some sharks go through over 30,000 teeth in their lifetime! The shape of the teeth largely depend on the shark’s diet. Sharks that feed mainly on mollusks or crustaceans have flattened teeth for crushing, while those that feed on fish have sharper teeth for gripping. 

 

Since most sharks are large, they have few natural predators. Unfortunately, like most wildlife, the biggest threat to sharks are humans. It is estimated that 100 million sharks are killed each year by commercial and recreational fisheries. This is due to a huge demand for shark fins, as well as their meat. This can have a devastating toll on ecosystems– Large, predatory sharks require a lot of food, so removing them from the ecosystem would mean too many prey are able to survive. This, in turn, would cause the prey to compete with each other for food, and would ultimately shift the food web. Like most predatory wildlife, sharks help keep ocean ecosystems in balance.  

 

Sharks have a bit of a scary stigma attached to them– Many people are afraid of getting in the water because of them. However, it is important to note that sharks do not swim around hunting for people. In fact, shark attacks are not as common as most people think. In South Carolina, the last fatal shark attack took place all the way back in 1852. With that being said, if you happen to be swimming and encounter a shark, there are a few steps you should take in order to stay safe. First, remain calm and do not behave erratically. Sudden movements and thrashing around can cause a shark to mistake you for prey. Try to move slowly towards the shore, and do not turn your back on the shark– Always keep them in view. 

 

As you can see, sharks are incredibly fascinating creatures, and we are so lucky to have them as part of the ecosystem in the Lowcountry! We hope that you found this article informative and helpful. As always, we thank you for reading and we hope to see you back on our blog soon! If you have any questions about our guided tours, reach out to us! At Coastal Expeditions, we are committed to introducing people to the wonders of the ecosystems of the Charleston area by providing guided tours and educational opportunities. If you’re looking to explore all that the Lowcountry has to offer, check out our offerings on our website to find the adventure which suits you best! We also offer kid-friendly tours as well as kids programs, camps, and kayak lessons. Our tours are led by knowledgeable, approachable naturalists and sea captains who are eager to answer your questions! Until next time, readers. Get out there and explore! Adventure awaits!

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@coastalexpeditions

Shem Creek in Mount Pleasant Rentals

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Take in the stunning beauty of local creeks and waters from one of our kayaks or SUPs. Walk-ups are welcome or call / text to book and we’ll be ready when you are. All gear and instruction provided.

Call or text 843.884.7684 to book.

Outpost Location

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If you really want to get a feel for the local history, identify the native wildlife, and get to special places, you'll need someone experienced to show you the way. We'll get you there.

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Isle of Palms Rentals

Offering Kayaks and Paddleboards

Take in the stunning beauty of local creeks and waters from one of our kayaks or SUPs. Walk-ups are welcome or call / text to book and we’ll be ready when you are. All gear and instruction provided.

Call or text 843.884.7684 to book.

Outpost Location

Need A Guide?

If you really want to get a feel for the local history, identify the native wildlife, and get to special places, you'll need someone experienced to show you the way. We'll get you there.

Check out our Isle of Palms tours.

Rent a Kayak or Paddleboard Click to Book via Text