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).
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)
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!
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?
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 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.
*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!
