10 Cool Shark Facts: Your Questions Answered!

bull shark bahamas, bull shark, bahamas
Bull Shark By Albert Kok~enwiki – Own work, CC BY-SA 4.0

The following are 10 Cool Shark Facts in a question and answer format.

1.How many shark species are there?

There are 512 described and 23 un-described shark species (according to Wikipedia)

2. Are sharks vertebrates?

Yes, sharks are vertebrates. Vertebrates have a backbone or spinal column. In the case of sharks, they have a spinal column made out of cartilage, not bone as in other vertebrates like bony fishes.

2.What is a group of sharks called?

A shoal (this applies to other fish as well)

3. What are baby sharks called?
Pups!

5. Are sharks endangered?
At least 143 species are on the IUCN red list with 210 more as data deficient (meaning we haven’t studied them closely enough to know how endangered the sharks are). But all sharks are in danger of becoming endangered due to overfishing, pollution, and other threats facing our oceans.

6. How many millions of years old are sharks?
The first sharks appeared 440 million years ago.

7. Which shark is the smallest? Which shark is the largest?
The smallest shark is the dwarf lantern shark, which grows to 7.9 inches (20 cm)
The largest shark is the whale shark, which can grow up to 60 feet (but is found to be 18-33 feet long on average)

8. Are sharks found in freshwater or saltwater?
Most sharks are found in the ocean in saltwater, but the river sharks are found in fresh and brackish water (slightly salty water) in Asia and Australia. The bull shark is unique in that it can live both in fresh and saltwater in tropical rivers worldwide.

9. Do sharks have swim bladders?
No, unlike the bony fishes, sharks don’t have swim bladders but the oil in their livers help them stay afloat.

And the final cool shark fact is:
10. How often do sharks eat?
It varies greatly between shark species. A great white shark can go a month without food after a full meal.

Also see: 10 Not-so-Scary Tiger Shark Facts

10 Interesting Great White Shark Facts

and Great White Shark’s Adventure at the Monterey Bay Aquarium

Fun quiz on sharks from NatGeoKids

The diversity of shark sizes graphic

Sharks on endangered species list

List of all sharks on Wikipedia

Interview with Shark Researcher Kristian Parton

Kristian Parton
Kristian Parton

This blog post is an interview with Kristian Parton, from the University of Exeter who is studying the effects of plastic pollution on sharks. He’s @KjParton on Twitter

What are some of the threats to sharks today?

KP- Blimey, where do I begin. It’s probably safe to say sharks (and rays) are some of the most threatened species in the worlds’ oceans. They have a variety of different threats, the most notable of which are without doubt overfishing and bycatch – these two practices are responsible for the removal of the greatest number of sharks from the seas. Then we move onto problems such as shark finning for traditional medicines, climate change, ocean acidification and plastic pollution!

Why should we save sharks?

KP- Well, not only are they absolutely awesome, they’re actually really important for the health and well-being of marine ecosystems. Sharks are top predators in the marine food web and consequently if you remove them this can have knock on impacts all the way down. I think it’s also vitally important to save threatened species for future generations. I remember the first time I saw a shark in the wild, it’s an experience I’ll never forget and I want the people who come after us to be able to experience that too.

How did you get started researching the impact of plastic pollution on sharks?

KP-Initially I was an undergraduate at the University of Exeter in the UK studying zoology, but took all the marine modules I possibly could. I knew I wanted to move straight into research after I graduated and have loved sharks since I was a young boy – so it was a no-brainer for me. It’s difficult to avoid the topic of plastic pollution at the moment, particularly in regards to turtles, seals and dolphins, but I read into a little bit more about how it might be impacting sharks and rays. It turns out the scientific literature is fairly scarce on the issue, so I dived in head first looking to expand our knowledge on how sharks and rays are really impacted by plastics – most notably via entanglement and ingestion.

Why did you found the Shark and Ray Entanglement Network?

KP-We founded ShaREN after our first publication a few weeks ago because we realised the issue of shark and ray entanglement in marine debris was severely underreported. In our research paper, we used Twitter reports to help document entanglement cases for sharks and rays and realised that it was occurring at higher levels on Twitter than it was in the scientific literature. We realised that the best way to try and collect more data on the topic was to create a citizen science platform where people around the world could submit their sightings of entangled sharks and rays. ShaREN is growing quickly and we’ve already had over 30 reports of entanglement since its creation a few weeks ago, but are always on the look out for more reports! If you do spot any entanglement incidents for sharks and rays, you can find the report form here: Shark and Ray Entanglement Network

Who’s your favorite Star Wars character(s)? (Both the interviewer and interviewee are big Star Wars Fans! Are you too? My favorites are the droids, R2D2 and BB-8)

KP-Hahah – that’s a tough question! I grew up around the prequels so I have a soft spot for them. I’d probably initially say Anakin, but he ends up going a bit mad (obviously) so I’d lean towards Ewan McGregor as Obi-Wan – what a legend! I can’t wait for the new TV series based around him.

Deep Blue is the Largest Great White Shark Ever Filmed

great white shark
Great White Shark Image by skeeze from Pixabay

The following is about Deep Blue, a Great White Shark most recently filmed in the Hawaiian Islands in January of 2019. She is estimated to be 20 feet long, weigh 2.5 tons, and to be 50 years old. She’ll keep growing throughout her long life. She was last filmed 2,400 miles away off of Guadalupe Island, which is off of Baja California, Mexico in 2013. She also was photographed in 1999.

Aha! I smell it—rotting whale flesh. There’s no smell quite like it. It gets my stomach rumbling, as I haven’t eaten in a month since the last whale carcass I feasted upon.

I can smell blood from miles away. This is necessary in the open ocean. Some dead whales sink and become food for the deep sea life. Thankfully others float, which is where I eat them.

There it is! I’ve found the dead whale. There is a feeding hierarchy, which means the biggest sharks eat first. That means the puny tiger sharks, who had been previously feeding on the whale, sensed me coming and are now gone. They have left me with my own personal banquet!

Great white sharks don’t travel in packs, but occasionally we’ll meet one another at opportunistic feedings such as this. I’ve swum past 2 other large female great white sharks in the area. I’m sure they’ll show up later if they haven’t already eaten.

Mmm, yummy. I open my mouth full of triangular, serrated and sharp teeth and close down on the squishy fat and meat of the dead whale. Blood fills the water around me. Wow, it feels good to have some food in my belly.

I take several more bites, closing my eyes right before I strike. Fortunately this whale can’t bite back and hurt my eyes!

Then some strange creatures show up. They jump off a boat and swim down alongside me. Humans are not on my menu. Not enough fat to even bother with!

Lights flash all around me from the humans. They stay out of my way as I continue to feed. Soon, I’ve gotten my fill of whale flesh. I’ll come back tomorrow when I’ve had time to digest some of the meat.

My belly is so big that I feel like I’m going to burst! I may look pregnant, but I’m not right now. My dozen pups were born while I was off the coastal waters. Now I swim off into the deep blue ocean to digest my huge meal.

Also see 10 Tiger Shark Not-so-Scary Facts

Book Review: The Shark Club by Ann Kidd Taylor

The Shark Club by Ann Kidd Taylor
The Shark Club by Ann Kidd Taylor

The Shark Club is an adult fiction novel about a love triangle between a shark-obsessed woman, her childhood love, and the newfound love in her life. It is chock full of facts about the ocean’s inhabitants and is reverent to the ocean itself. It was nice to see written what it’s like to SCUBA dive-not just the mechanics, but the thoughts and emotions that one feels while immersed in the ocean.

As for the love triangle, it wasn’t obvious at the start or through the book whom she’d end up with, and the ending was a bit surprising at first, but was satisfying once I thought about it.

It would be one thing if it were a purely love triangle, but it’s more like a square or even pentagon if you count Maeve’s obsession with sharks despite being bitten by one as a child, and her meeting the daughter of her ex-fiancee, his infidelity the reason for her breakup with Daniel.

Maeve’s love of sharks hindered her first relationship with Daniel as she “chose” the sharks (on an expedition) over Daniel right before they were to be married. Many people are addicted to work and prize it above all else, and Maeve is one of them. I think it’s noble that she’s so committed to her job as a shark biologist and always jetting off to far flung research sites around the world, but it’s clear she has regrets leaving Daniel right before their wedding (and he cheats on her and has a child out of wedlock).

When Maeve meets Hazel, who is 6 years old, she “falls” for the scientist-in-the-making and nurtures her love of sharks and prehistoric sea monsters. They form the “Shark Club” with Maeve, Daniel, and Hazel as members. Maeve and Hazel search for shark teeth on the beach and later make a necklace from it. It’s a cute storyline, and critical to understanding the ending.

All the ocean facts Taylor mentions rang true too me as a marine biologist, but I did wonder why she had to round up the figure of how many sharks a year are killed to 80 million. Usually 73 or 100 million sharks killed a year is the figure given. It’s hard to be accurate with such a high number, and clearly it’s not sustainable to kill that many sharks a year.

The book pays respect to Dr. Sylvia Earle, “Her Deepness,” or as I like to say, the female Jacques Cousteau. She is the most prominent oceanographer alive today, having traveled to the deep ocean and spending 7,000 hours underwater in her life. The protagonist, Maeve, names a lemon shark she likes after her. The author also mentions the on-going lemon sharks studies at the Bimini Research Station in the Bahamas. The book also mentions Dr. Andrea Marshall, also known as “The Queen of the Mantas.” The author mentions her non-profit research facility (The Marine Megafauna Foundation) in Mozambique, Africa. Lastly she mentions Julia Whitty, the author of “The Fragile Edge,” about a woman’s relationship to the ocean.

The side story with her fraternal twin Robin is important, but the ending with him seemed out-of-character and less plausible than the rest of the book. But he, and her aunt Perri who raised them when their parents died, are important in Maeve’s life and that’s why their storylines are included.

I haven’t mentioned the rest of the love triangle, Maeve’s colleague from the Bahamas. Nicholas is technically still married and workplace romances are frowned upon. So Nicholas and Maeve were never officially together, though Nicholas comes to visit her at her Aunt Perri’s hotel where Maeve and Robin grew up and still live. They finally discuss a possible relationship, but put it on hold until Nicholas resolves his marriage in England.

The hotel is in sunny Florida and Maeve has a job there at the Conservancy (forgot full name). If only we all had jobs that would let us fly off to exotic locations for months at a time and still have a job when your return home. This is another reason for you to be jealous of Maeve, besides having two men pine for her.

If you happen to be scared of sharks, I hope you come away from this book with a healthy respect for them. If you love the ocean-especially being in or on it- then run, don’t walk to buy or check-out this book. I requested that my local library buy a few copies and they did! If you like romances, don’t worry as the Maeve biology stuff takes a back seat to the romance.

In short, those who love the ocean will love this book. Those looking for a different sort of love triangle (Daniel, Nicolas, Hazel and the sharks in general) will enjoy this book. There’s no graphic sex so this book could be read by young adults looking to read something beyond teen romances. If there hadn’t been sharks in this book I wouldn’t have picked it up, but fortunately the shark biologist premise sucked me in for 271 pages.

10 Tiger Shark Not-So-Scary Facts

notice the beautiful tiger-like stripes on the Tiger Shark photo by Edwar Herrano
notice the beautiful tiger-like stripes on the Tiger Shark photo by Edwar Herrano via Undersea Hunter Group

10 Tiger Shark Facts

1. A tiger shark’s stripes fade as he gets older.

2. Tiger sharks are the second most dangerous sharks to humans (after great white sharks)

3. Tiger sharks eat a variety of animals, including sea turtles (their teeth can crack their shells), seabirds, stingrays, sea snakes, fish, mollusks, crustaceans, small sharks and dead whales.

4. Tiger sharks will eat literally anything. They have been found with garbage, plastic bags, license plates and old tires in their stomachs.

5. Tiger sharks on average grow to 10-14 feet long(3-4.3m) (but can grow up to 20-25 feet long [6.1m-7.6m]) and weigh 850-1400 pounds (386-635 kg)(up to 1900 pounds [862kg]).

6. The only sharks larger than the tiger sharks are whale sharks, basking sharks and great white sharks.

7. Tiger sharks generally live alone, but when they do come together in groups they have a social hierarchy based on size. The larger sharks get first dibs on the food source, such as a dead whale.

8. Tiger sharks are killed for their fins, skin and meat. Their liver has high levels of vitamin A and are used in supplements. Their fins are used in the dish, shark fin soup.

9. Tiger sharks are considered “near threatened” (to extinction) on the IUCN Red List. They are just one spot above of “least concern.”

And the final tiger shark fact is:
10. A female tiger shark’s gestation period is 14-16 months, and she can give birth to 10-82 pups.
Also see:
Meet Deep Blue-The Largest Great White Shark Ever Filmed

Great White Shark’s Adventure at the Monterey Bay Aquarium

For more information: National Geographic’s Tiger Sharks
Shark’s World Information on Tiger Sharks
Tiger Shark Facts

10 Interesting Great White Shark Facts

Great White Shark Facts: Photo credit: Elias Levy via Visualhunt / CC BY
Great White Shark: Photo credit: Elias Levy via Visualhunt / CC BY

10 Interesting Great White Shark Facts

1. Great white sharks are the largest predatory fish in the oceans.

2. The great white shark’s scientific name Carcharodon carcharias means ragged tooth.

3. The largest great white sharks recorded were over 20 feet long (6.1 m) and weighed over 5,000 pounds (2,268 kg).

4. Like all sharks, great white sharks have a “sixth sense” that detects electrical impulses such as your heart beating.

5. Adult great white sharks eat sea lions, seals, small toothed whales, sea turtles and carrion (meat from already dead animals). Young great white sharks eat mainly fish and rays.

6. Great white shark pups are 50-60 pounds at birth (22.7-27 kg), and 47-59 inches (120-150 cm) long.

7. Great white sharks are considered warm-blooded (like mammals) or endothermic. Their body temperature is warmer than the water surrounding them.

8. The only enemies of great white sharks are killer whales, larger sharks, and humans (who kill up to 100 million sharks of all species per year).

9. Recent studies suggest great white sharks use their excellent eyesight to spot their prey.

And the last great white shark fact is:
10. The IUCN (International Union for the Conservation of Nature) considers great white sharks “vulnerable” to extinction (and not endangered-yet).

Also see: 10 Cool Shark Facts: Your Questions Answered!

Great White Shark’s Adventure at the Monterey Bay Aquarium

Children’s Book Review: If Sharks Disappeared by Lily Williams

Book: "If Sharks Disappeared" by Lily Williams
Book: “If Sharks Disappeared” by Lily Williams

If Sharks Disappeared, is written and illustrated by Lily Williams, and published by Roaring Brook Press. It is a much needed book about sharks. There are numerous children’s books about sharks, but not many show sharks in a positive light.

Instead of painting sharks as blood-thirsty human eaters, Williams shows how important sharks are to the ocean ecosystem. There is one “scary” picture of a great white shark, but it is cartoon-like enough not to be really scary. Otherwise Williams’ charming artwork depicts sharks as not scary and almost friendly (which most are!).

My favorite page shows a couple dozen sharks of different sizes and shapes. As a marine biologist it was a puzzle to try and figure them all out as they are not labeled. I also liked how there was dark-skinned girl as our guide throughout the book as showing diversity is becoming important in children’s books.

The “if sharks disappeared” portion of the book is not alarmist, but rational showing literally an ecosystem without sharks. The backmatter consists of a glossary and more information about how sharks are in trouble and what you can do to save them.

All in all, not just shark-loving kids will like this book. Most readers will be delighted with Williams’ shark artwork and will learn more about sharks at the same time. I highly recommend that you check out If Sharks Disappeared! (link to order)

Hammerhead Sharks at Cocos Island

Hammerhead Sharks, Cocos Island Photo by Edwar Herreno, Undersea Hunter
School of Hammerhead Sharks, Cocos Island Photo by Edwar Herreno, Undersea Hunter

Ah, it feels great to swim around in a school of Hammerhead Sharks. My name is Sam. Here at Cocos Island, off of the shore of Costa Rica, I can roam free with hundreds of other hammerhead sharks. I used to swim in schools of thousands of hammerhead sharks before the humans came. In other areas of the oceans, populations of all types of sharks have been decimated.

Unfortunately, fishermen target sharks for their fins. Ouch, I need my fins to steer and swim, thank you very much. The shark fins are used in a soup served in many Asian countries, mainly China.

Fortunately, there are shark fin bans around the globe. The United States for instance, has 11 states and 3 territories that ban the sale, trade and possession of shark fins. Recently, on June 23, 2016 a bill called the Shark Fin Elimination Act of 2016 (S.3095/H.R. 5584) began its call to action in the United States Congress. This bill would ban the selling of shark fins across the entire United States. Stay tuned for updates!

Another reason for hope is Marine Protected Areas or MPA’s. There are over 6,500 MPA’s around the globe that fully or partially protect the flora and fauna that live there. These MPA’s make up less than 2 percent of all the world’s oceans though. Humans can do better than that! In contrast, up to 15 percent of land is protected.

Animals such as giant manta rays and whale sharks sometimes come to Cocos Island. They are protected while here, but once they swim into international waters, they are fair game for fishermen. That’s why it’s so important that scientists tag these migrant animals and see where they go. For instance, it isn’t known where female whale sharks give birth. Once humans find out, it will be important to protect the whale sharks’ pupping grounds.

I hope you’ve enjoyed my lesson today-please come visit me and my friends someday! Cocos Island is one of the best SCUBA diving sites in the world!

A Great White Shark’s view of Discovery Channel’s Shark Week

great white shark
Great White Shark photo by: Cherilyn Chin

Hi, my name is Boo. I’m the star of Shark Week on the Discovery Channel. At least my species is. I’m a great white shark. My name is Boo because I like to sneak up on my prey. The name “shark” already strikes terror in humans, but adding the “great white” part makes me sound scarier. I must admit, my mouthful of teeth and red gums are very intimidating, and aren’t very pretty. But my mouth sure does scare my prey, which is what matters most to me!

I don’t like how sharks are portrayed during Shark Week. We’re not man-eating mindless machines. I gotta eat, and over millions of years, great white sharks have become very proficient at eating other animals. Eating live prey is messy with blood everywhere in the water. Did you know I can smell one drop of blood in 25 gallons (100 liters) of seawater?

I could have been named a “great gray shark” because my back is gray. This is due to countershading. That means that when animals see me from below, my white belly blends into the sunlight above me. When an animal looks at me from above, my gray back blends into the dark water below me.

I’m not like those show-off great white sharks that live off of South Africa. I don’t jump clear out of the water when catching my prey. Instead I sneak up on my prey from below. I live off the coast of California, and I like to eat sea lions, seals, small toothed whales and carrion (food I scavenge).

I have 300 triangular teeth several rows deep. The teeth are continually being replaced so I never have to see a dentist.

I have no natural predator, except for orcas or killer whales. I have an unnatural predator in humans. Up to 100 million sharks annually are killed, mainly for their fins. The fins are used in shark fin soup, a delicacy in many Asian countries.

I would be safer if I just stayed near California, but a lot of great white sharks travel to the “White Shark Café” between Baja California and Hawaii. Those waters are not protected by any one nation. Why we do that is a mystery to humans, and I ain’t gonna be the one who talks!

I hope if you tune into Shark Week this week that you remember who the true killers are (humans) and that you remember me, Boo. I’m not that scary after all, right?

The 3 Most Pressing Ocean Issues for World Oceans Day

dried shark fins photo by Paul Hilton
Actress Sharon Kwok and 30,000 dried shark fins in Hong Kong: photo by Paul Hilton

This World Oceans Day I would like to reflect on the state of the oceans. There are 3 major issues facing the oceans. They are (in no particular order):

1. Overfishing
2. Climate Change
3. Pollution

1.Overfishing

*It is estimated that 90% of all large fish (and many smaller species) have been fished out of the oceans.

*According to the FAO (Food and Agriculture Organization of the United Nations), 53% of the world’s fisheries are fully exploited, and 32% are overexploited, depleted, or recovering from depletion.

Fishing can be too efficient with entire schools of fish being caught at once. Fishing can also be incredibly wasteful with by-catch such sea turtles, whales, and sharks when only one fish is being sought (like tuna).

Shark finning is a prime example of overfishing. It is estimated that 100 million sharks are killed a year. They are killed mainly for their fins, which is used to make shark fin soup. Sharks are top level predators, and their naturally low numbers in the wild reflect that. As a consequence, they are slow to reproduce and cannot keep up with the current levels of fishing.


2.Climate Change

Climate change includes global warming, sea level rise, and ocean acidification.

Global warming will cause the oceans to become warmer, and may substantially change ocean circulation patterns. This may disrupt natural feeding cycles and may affect the weather. Some ocean species, like coral, only have a narrow range of temperature tolerance and will die if the oceans become too warm.

Global warming will cause polar ice caps to melt, and sea level will rise accordingly. Some island nations will be flooded out of existence.

Ocean acidification occurs when the pH of the seawater decreases and becomes more acidic (think soda pop). This is because the oceans absorb about a quarter of all carbon dioxide (a greenhouse gas) in the atmosphere. Ocean acidification will make it harder for some animals to build their calcium based shells, and cause many species to go extinct. Ocean acidification has other deleterious effects that are just being discovered.

sea turtle eating plastic
Sea turtles often mistake plastic bags for jellyfish: photo by dep.state.fl.us

3.Pollution

Pollution can come in many forms, like untreated sewage, agricultural runoff, or sedimentation. The worst offender by far is plastic pollution. Every imaginable bit of plastic ends up in the oceans one way or another. From plastic bags, to unidentifiable microscopic bits, ocean denizens at all levels of the food chain are affected.

Possible Solutions
While the outlook for the three problems mentioned sound bleak, there is hope.

*Marine protected areas (MPAs) can help fisheries become sustainable by being a nursery for the fish caught right outside the MPA borders. Unfortunately only 1% of the oceans are protected.

*You can help by eating only sustainably caught seafood. Download the Monterey Bay Aquarium’s Seafood Watch guide as a start.

*Curbing carbon dioxide emissions (i.e. using less fossil fuel) by using other alternative energies will help tremendously in slowing down ocean acidification.

*Driving less and using public transportation are ways to help reduce greenhouse gas emissions. Also consider getting solar power for your home or workplace.

*Plastic pollution is preventable, especially by cutting down the use of single use plastic bags (bring your own bags to the grocery store!), and by supporting local plastic bag bans. We can also pressure manufacturers to use only recyclable packaging.

So this World Oceans Day, please realize that everyday each one of us can make a difference in the health of our oceans!