Sharks (Primary)

SHARKS
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Slide 1: Slide
Social StudiesHistory+34-6 Grade6th,7th Grade

This lesson contains 42 slides, with interactive quizzes, text slides and 1 video.

time-iconLesson duration is: 60 min

Introduction

Sharks are under threat from a number of issues, including poaching and by-catch in nets of the commercial fishing industry. Many shark species are endangered as a result of poaching.

Instructions

In this lesson we will be talking about sharks and learn about the issues threatening their survival.

Time: 60 minutes

Contact: education@seashepherdglobal.org
© Sea Shepherd 2021

Items in this lesson

SHARKS

Slide 1 - Slide

This lesson is provided by Sea Shepherd.  Sea Shepherd is a marine conservation organisation with a mission to protect the ocean and marine wildlife.  Sea Shepherd works globally on a range of issues impacting the ocean, running numerous direct action campaigns each year.  These campaigns also include the protection of sharks.
What you already know...
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Evaluate your knowledge

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Watch  the video

Slide 2 - Slide

During the lesson we will use these icons to identify the learning actions.
Impacts of overfishing on sharks.
Sharks and the issues threatening them.

Slide 3 - Slide

In this lesson we will be talking about sharks and learn about the issues threatening their survival.

INTERACTIVE JOIN – ask students to go to www.LessonUp.app


Slide 4 - Video

Empty ocean by 2050
Scientists estimate that by 2050 the ocean ecosystem will be on the verge of collapse, empty of fish and marine wildlife, unless urgent action is taken on the issues impacting on the oceans and marine wildlife.

Show this video (2.53min), which explains how important all species are to our planet.
https://www.youtube.com/watch?v=TLcA31VRlRU

Discuss the video with the class and what it means.

Sharks have lived on planet earth for 450 million years.
400 known shark species.

Sharks have lived on planet earth for 450 million years.
400 known shark species.

Slide 5 - Slide

Sharks
Sharks have existed on this planet for over 450 million years, well before dinosaurs.  

There are currently over 400 species of sharks that have been identified, but 143 of those species are threatened with extinction.


Who likes sharks and why?
For those that don't, what is it about
sharks you don't like?

Slide 6 - Open question

Ask students to answer via www.LessonUp.app or discuss in classroom.

“Who likes sharks and why?”

“For those that don’t, what is it about sharks you don’t like?”

What sharks species do you
know and what facts
do you now about sharks?

Slide 7 - Mind map

Shark species
Ask students to answer via www.LessonUp.app or discuss in classroom.

“Which shark species can they name and what key facts do they know about that species?”

Over 100 million tonnes fish caught each year.
Whale sharks

Slide 8 - Slide

Whale sharks
The largest shark is the whale shark. Whale sharks grow are up to 13m (42.6feet) and are slow movers compared to other shark species. Like the baleen whales they filter feed, mainly on plankton.

Status – Endangered.

Over 100 million tonnes fish caught each year.
Hammerhead sharks.

Slide 9 - Slide

Hammerhead sharks
Hammerhead sharks are called this because of the shape of their heads. While many other sharks are solitary the hammerhead swim in schools (also called a shiver) during the day and at night when hunting, they head their own way.  They can grow to about 6 m (20feet) long and weight up to 600kg (1,323lbs).  

Given where their eyes are positioned it means they can see above and below themselves all the time.

There are several species of hammerhead sharks: the Greater Hammerhead and Scalloped Hammerhead are currently listed as critically endangered. Smoothed Hammerheads are listed as vulnerable and with declining populations will soon be classified as endangered.

Over 100 million tonnes fish caught each year.
Great white sharks

Slide 10 - Slide

Great White Shark
The Great White Shark is the one most recognised. They can measure up to 8m (26feet) long and weight over 3,000kg (6,614lbs).  Great white sharks can live up to 70 years.

With declining populations white sharks are also listed as vulnerable.


Over 100 million tonnes fish caught each year.
Oceanic white tip sharks

Slide 11 - Slide

Oceanic White Tip Shark
This shark is known by several names and lives in tropical and warm seas. It is a member of the requiem shark family, who are slower swimmers.  It lives up to 20 years and is on average up to 2.5m (98 inches) and weights up to 70kg (150lbs).

Oceanic white tip sharks hunt in schools and are know for their feeding frenzy. They are very curious and are known to follow ships.

Status: With declining numbers they are critically endangered.


Leopard Shark
Bull Shark
Nurse Shark
Scalloped Hammerhead Shark

Slide 12 - Drag question

Match the images
Using www.LessonUp.app ask students to match the image of the shark to its name.

Over 100 million sharks caught annually.
Shark babies.

Slide 13 - Slide

Shark babies
Ask students to answer via www.LessonUp.app or discuss in classroom.

“How sharks are born – hatch from eggs or live birth?”

All sharks hatch their young in eggs, most sharks like the Great White Shark hatch the egg inside and the baby develops until it is born alive and fully functional.  Tiger sharks are also fully functional at birth. A tiger shark may have anywhere between 10 to 80 babies.

Other species lay eggs and hide them in pockets in rocks or coral to protect them until they hatch.   Shark babies are called pups.






Shark features:
  • Teeth, or
  • Filter feeders

Slide 14 - Slide

Shark features
One defining feature is how they feed. They either have:
  • Teeth, or
  • Filter feed.

Most shark species have teeth, but theirs are embedded into their gums, rather than bone like ours. While we have one row of teeth they have several.  

A shark can lose a tooth every 8 - 10 days. As they lose a tooth a new one moves up from the rows behind.  

Filter feeds, whale sharks, basking sharks and the megamouth shark, feed as they swim. They open their mouths filter plankton and zooplankton from the water.






What do sharks eat?

Slide 15 - Slide

What do sharks eat?
Most sharks are carnivorous so they like to eat other animals. They prey upon fish, dolphins, whales, seals, turtles and sea birds.  

Most are considered to be scavengers.  They will find sick and weak fish, or what they can find on the ocean floor, such as dead whales.

Sharks do have strong hunting skills and can surprise their prey with their speed.   Some shark species do hunt in groups. Sharks will try to disable their prey and then drag them to the ocean floor to drown them.

Despite their skills most sharks can only tell if something is really food by taking a test bite. They have been known to take bites out of surfboards, buoys and other rubbish mistaking it for food.

Young sharks especially, while honing their skills, will make these mistakes.

Over 100 million sharks caught annually.
What do sharks eat?  Can you tell the difference?

Slide 16 - Slide

What do sharks eat?
While some people fear sharks and being bitten, as a matter of fact most sharks do not see humans as food.  They do however like seals and turtles.

Have a look at this image.  Ask students if they think a shark would be able to tell the difference?

Do you know what each of these are?
- Seal, surfer and sea turtle.


Over 100 million sharks caught annually.
Smell

Slide 17 - Slide

Smell
Sharks have an amazing sense of smell and can detect blood in the water miles away.  They can use this when searching for injured marine wildlife to feed on.  

Ask students:
“What circumstances would make it dangerous to go in the water if sharks can smell blood?”

Discuss what action they should take to ensure they are safe from a shark encounter.

Examples:
  • Don’t go into the water if you have a cut and are bleeding.
  • Avoid swimming if there is someone fishing in the area.
  • Don’t go into the water if there are other fish feeding in the area.
  • Don’t go into the water if there is dead marine wildlife in the water or on the beach, like stranded whales.

Over 100 million sharks caught annually.
Sound

Slide 18 - Slide

Sound
Sharks can also hear really well, they have millions of hair cells in their ear that help them sense vibration in the water.

This allows them to detect sounds from far away. Because sound travels further under water sharks can hear up to 400 metres away. Sharks can detect the movement of a fish or marine animals splashing around in the water.

What circumstances would make
it dangerous to go into the water
if sharks can hear from a distance?

Slide 19 - Mind map

When should you stay out of the water?
Ask students to answer via www.LessonUp.app or discuss in classroom.

“What circumstances would make it dangerous to go in the water if sharks can hear from a distance?”

Examples:
  • If there are seals or dolphins in the water.
  • If there is someone fishing in the area.
  • If there are other fish feeding in the area.
  • If there are large schools of fish or what is called a bait ball.

ELECTRORECPTION



What circumstances would make it dangerous to go in the water, if sharks can use these sensors rather than their eyes?

Slide 20 - Slide

Electroreception
Sharks also have something called electroreception. Around their face they have tiny black dots that are like sensors, that pick up on electrical pulses.  

When they get close to prey these sensors help to guide the shark to the exact location.

They actually don’t use their eyes to see close up, they roll their eyes back into their head to protect them and use their sensors to guide them to their prey.

Ask students
“What circumstances would make it dangerous to go in the water, if sharks can use these sensors rather than their eyes?”

Examples:
  • If there is poor light where you can’t see the shark – dawn and dusk are especially bad times when sharks are more likely to be feeding.
  • If the water is murky.


A healthy ocean needs sharks.
Fins and movement.
First Dorsal Fin
Second Dorsal Fin
Caudal Fin
Pectoral Fins
Pelvic Fins

Slide 21 - Slide

Fins and movement
How do sharks move through the water?  

The shark’s fins help it to move through the water and give it balance.

They have a number of different types of fins. (See diagram)

Without fins the shark would just sink to the ocean floor and drown.


How do you think sharks breathe?

Slide 22 - Open question

How do sharks breathe?
Ask students to answer via www.LessonUp.app or discuss in classroom.

 “How do you think sharks breathe?“  

There are two ways of breathing, one requires the shark to constantly be moving through the water. Movement helps push water through their gills and they extract the oxygen from the water.  

The second method used by some sharks, particularly when they are resting, is to suck water into the gills and extract the oxygen.  They don’t have to rely on movement.



Why are sharks important to the ocean ecosystem?

Slide 23 - Open question

Why important to the ocean ecosystem?
Ask students to answer via www.LessonUp.app or discuss in classroom.

 ‘Why are sharks important to the ocean ecosystem?’

Sharks help to keep ecosystems in balance.
Their scavenger behavior helps to keep the ocean floor clean of dead animals.

They help to keep other species stronger, by preying on the old, sick and weak members.

Sharks help to control other predator species, particularly in reef ecosystems. Controlling smaller predators helps to protect the smaller species that keep reef ecosystems flourishing. Sharks are crucial for healthy reef ecosystems.


Balancing ecosystems.
Predators

Slide 24 - Slide

Predators
Sharks have very few natural predators, some species have been known to prey on other sharks but the main predator is the killer whale or Orca.  

What are the main
threats to sharks?

Slide 25 - Mind map

What are the main threats to sharks?
Ask students to answer via www.LessonUp.app or discuss in classroom.

“ What are the main threats to sharks?”

“Why are they becoming endangered?”


400 known shark species.
Only 47 species have healthy populations.
Humans - Over 100 million sharks are killed each year.

Slide 26 - Slide

Humans
The main threat to sharks are humans.
Over 100 million sharks are killed each year by humans.

400 known shark species.
Only 47 species have healthy populations.
Shark poaching.

Slide 27 - Slide

Poaching
Fishing operations are set up to intentionally take sharks illegally. These poachers are part of the illegal network that supplies shark fins and shark liver oil, contributing to the death of millions of sharks each year.     

Shark meat.
Shark meat.

Slide 28 - Slide

Why are sharks targeted by poachers?
Some are caught for food, but not as many as are thrown away.  Shark meat is sold by many names around the world.  

Oceanic Whitetips are one species targeted for their meat.

Ask students:
“Which names have you seen for shark meat?”


Shark finning.
Shark finning.

Slide 29 - Slide

Shark finning
The majority of sharks caught are killed just for their fins.

Most of the shark is not used for food, the poachers just cut the fins off the shark and then throw the shark back into the ocean to drown.  

Shark fins are used for herbal remedies, but most are just used to make Shark Fin Soup. Shark Fin Soup has no real taste, but it is a sign of wealth in some Asian cultures and people pay a lot of money for it.


Fins are used for herbal remedies and Shark Fin Soup.

Shark Fin Soup has no health benefits or real taste, but it is a sign of wealth in some Asian cultures and therefore people pay a lot of money for it. This is the main cause of demand for shark fins globally.

Shark liver oil.
Shark liver oil.

Slide 30 - Slide

Shark liver oil
Along with their fins sharks are killed to extract the oil from the liver.

Shark liver oil has been used as a folk remedy for healing wounds and many other ailments, including cancer. These claims have not been scientifically tested.

It was once believed that sharks didn’t get cancer and therefore must be immune. We now know that sharks do get cancers and tumors.


Shark meat - known by many names.
By-catch in commercial fishing nets.

Slide 31 - Slide

By-catch
Sharks are often caught as by-catch in the nets of the commercial fishing industry.

By-catch means that they are not the intended catch and they either do not want or cannot legally sell the catch. They mostly get thrown back into the oceans as rubbish, a real waste of life.  

Shark fishing or finning is banned in many countries, making it often illegal to keep this by-catch.

Given how sharks breathe it is difficult for them to survive extended periods of time trapped in fishing nets.  They can’t move around.  Which means most trapped in commercial fishing nets will not survive.


Shark meat - known by many names.
Abandoned, lost and dumped fishing gear.

Slide 32 - Slide

Abandoned, lost and dumped fishing gear
ALD fishing gear or ghost nets are difficult to see floating in the ocean, trapping unsuspecting marine wildlife, including sharks.

For more information on this topic see the Lesson: Abandoned, Lost and Discarded fishing gear.


How are 100 million sharks caught?
Overfishing the ocean

Slide 33 - Slide

Overfishing
With 90% of the ocean already over exploited this means that food sources for marine species, including sharks, are disappearing.

As a consequence sharks are coming closer to shore to chase food sources.

When sharks are spotted, and shark sightings increase, it often is just a sign they are hunting and following schools of fish.

Poaching - using nets and longlines,
targeting fins and shark liver oil.
Shark culls and deterrent measures.

Slide 34 - Slide

Shark culls and deterrent measures
After a shark incident there are often calls to cull sharks to protect people. The aim is to remove sharks from the area.

Ask students:  “If you remove a few sharks from the area, what do you think will happen?”
  • New sharks will move in and take over the territory.
  • Sharks migrate between areas so new ones will pass through the area.
  • If there is a food source in the area, baitfish or dead whale, it will continue to attract sharks.

By-catch in commercial fishing nets.
Shark nets and drum lines.

Slide 35 - Slide

Shark nets and drum-lines
To protect swimmers at beaches shark nets might be installed or they may use drumlines. These are designed to either keep the sharks out of the swimming area, or attract them to the drumline where they will be caught on baited hooks.

Ask students:
“What issues can you see with using these methods to protect swimmers?”

  • Other marine wildlife in the area might be caught or stopped by the nets, affecting the balanced ecosystem.
  • Other marine wildlife also may get caught on the drumlines trying to take the bait.
  • Baited drumlines will attract sharks to the area, when they smell the bait.
  • Non target species, like migrating whales, also get caught in the nets or drumlines.
  • During bad weather the nets could come loose, allowing sharks to pass through.







Should we kill sharks to protect humans?

Slide 36 - Slide

Should we kill sharks to protect humans?
Ask students: “Do you think it is necessary to kill sharks so people can swim in the ocean?”

Reasons why sharks shouldn’t be culled
  • The ocean is home to sharks and all marine wildlife, humans enter the ocean for entertainment.
  • Sharks are just looking for food, to survive.
  • Most sharks don’t intentionally kill people. Usually the shark will take a test bite to see if something is edible.  Unfortunately shark teeth are very sharp and can easily cause fatal wounds, causing the prey to bleed to death.
  • Shark culls are cruel, they use bait to intentionally lure sharks and randomly kill them.

Fact: On average less than 100 people a year are injured or die around the world due to shark encounters. Over 100 million sharks are killed each year.  

More people die each year by falling from ladders, getting stung by bees, or drowning at beaches, than people do from shark encounters.  


What are the alternatives to
protect humans, rather than
shark culls, nets or drumlines ?

Slide 37 - Mind map

Alternatives
Ask students to answer via www.LessonUp.app or discuss in classroom.

 “What are the alternatives to protect humans in the ocean, rather than shark culls, shark nets or drumlines?’

Some of the alternatives available:
  • Eco-barriers – instead of shark nets these are a hard barrier that marine wildlife don’t get trapped in.
  • Shark shields and other personal devices that swimmers or surfers can wear or put on the board to deter sharks coming near.
  • Shark spotters, or aerial surveillance by helicopters or drones to monitor for sharks and warn swimmers.

Alternatives previously discussed:
  • If sharks are in the area don’t go in the ocean.
  • Don’t swim near anyone fishing.
  • Don’t swim near seals if sharks are around.
  • Don’t swim or surf near bait balls – schools of baitfish.
  • Don’t go in the water if you have an open wound that is bleeding.
  • Don’t enter the water when there is poor light and you cannot see sharks – dawn and dusk are especially bad times when sharks are more likely to be feeding.
  • If the water is murky.

Some shark species, like oceanic whitetips or tiger sharks, are more dangerous to be in the water with due to their curious nature. It is important to remember these are wild animals in their own habitat.

What can we do to help protect
sharks from becoming extinct?

Slide 38 - Mind map

How can we protect sharks?
Ask students to answer via www.LessonUp.app or discuss in classroom.

 “What can we do to help protect sharks from becoming extinct?”

  • Help stop the sale of shark fin and shark liver oil products.  Reducing the demand to stop the illegal activity.
  • Reduce the demand for shark meat.
  • Create awareness about the declining rate of sharks in the ocean.
  • Help to change peoples’ attitudes towards sharks, reducing the fear of sharks and creating awareness on how to protect themselves when encountering a shark.

Some suggested answers:
➢    Do not buy shark products.
➢    Help raise awareness.
➢    Push for your government to ban shark fishing and the sales of shark fins.


Write down three things you have learned?

Slide 39 - Open question

What did you learn?
Ask students to answer the following question using www.LessonUp.app or discuss in the classroom.  

“Write down three things you have learned?”


Write down one thing you didn't understand?

Slide 40 - Open question

What don’t you understand?
Ask students to answer the following question using www.LessonUp.app or discuss in the classroom.  

“Write down one thing you didn’t understand?”


Slide 41 - Slide

Sea Shepherd Case Studies cover a number of Sea Shepherd campaigns and show videos of some of our work to help protect sharks.  These can be used to enhance the learning experience from this lesson.

www.seashepherdglobal.org

Slide 42 - Slide

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