Sea Turtles (Junior)

SEA TURTLES
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Social StudiesHistory+3Age 51st,2nd Grade

Cette leçon contient 29 diapositives, avec quiz interactifs, diapositives de texte et 1 vidéo.

time-iconLa durée de la leçon est: 45 min

Introduction

This lesson discusses sea turtles and why they are important for our ocean.

Instructions

This lesson is about sea turtles, some of the things harming them and what everyone can do to help them.

Time: 45 minutes

Contact: education@seashepherdglobal.org
© Sea Shepherd 2021

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SEA TURTLES

Slide 1 - Diapositive

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.  Sea turtles are one species that Sea Shepherd is fighting to protect.
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Watch  the video

Slide 2 - Diapositive

During the lesson we will use these icons to identify the learning actions.
Illegal poaching endangering sea turtles.
Protecting sea turtles.

Slide 3 - Diapositive

This lesson is about sea turtles, some of the things harming them and what everyone can do to help them.

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

Current sea turtle species appeared
over 100 million years ago.
Current sea turtle species appeared over 100 million years ago.

Slide 4 - Diapositive

Sea turtles have existed for over 100 million years, since the time of the dinosaurs.

Today they are disappearing from the ocean as their numbers reduce.  We have to help protect them.


Current sea turtle species appeared
over 100 million years ago.
Features of a sea turtle.

Slide 5 - Diapositive

Sea turtle features
Ask students to identify features from the image, or facts they know about sea turtles?

Facts about sea turtles shells:
  • Shells are made of two layers, one of bone and one of keratin scutes (what finger nails are made of).
  • Scutes are like big scales, they are what make the pattern on the back of the sea turtle.
  • The leatherback turtle doesn’t have scutes, it has a leathery skin. 
  • A sea turtle cannot retract it’s head into the shell.

Sea Turtle species

SEA TURTLE SPECIES

Green Sea Turtles

Grow up to 1.5m (4.9feet).

Weight up to 300kg (660lbs).

Green skin and hard shells.

Live up to 80 years.




Slide 6 - Diapositive

Green sea turtles
There are 7 main species of sea turtles.

Green turtles don’t get their name from the colour of their shell, which is anywhere from brown to olive.

They’re called green turtles because they have green skin. They have a hard shell. They live mainly in shallow water near the coast, where they find lush sea grass beds to feed on.  

Green turtles will live up to 80 years if not longer. Most of the time they will only ever come to shore to nest.   

They grow to 1.5m (4.9feet) long and weight up to 300kg (660lbs).

Sea Turtle species

SEA TURTLE SPECIES

Hawksbill Sea Turtle

Weight up to 70kg (154lbs)

Grow up to 90cm (3 feet).
   
Hawks beak, which allows to get food from coral reefs.
   




Slide 7 - Diapositive

Hawksbill sea turtles
The Hawksbill turtle is really interesting; they get their name from the sharp, curved beak that looks like a ‘hawk’s beak’. The beak allows it to get food from crevices in coral reefs. The shell is very colorful and has a saw-like edge to it.  

Hawksbill turtles can grow up to 70kg (154 pounds) and grow to around 90cm (3 feet).

They can live up to about 50 years. Hawksbills are the most endangered of all sea turtles.

Sea Turtle species
SEA TURTLE SPECIES
 
Olive Ridley
    Grow up to 70 cm (2.5 feet) Weight up to 45kg(100lbs).
    Olive green shell colour.
  

Kemp Ridley
    Grow up to 66 cm (2feet)
Weight up to 50 kg (110 lbs).
    Dark green shell, while underside is white or yellowish.

Slide 8 - Diapositive

Olive & Kemp Ridley sea turtles
The olive ridley sea turtle has an olive green shell and grows to around 70 cm (2.5 feet). It weights around 45kg (100pounds).

The kemp ridley has a dark green shell and a white or yellowish underside.  It grows up to 66 cm (2 feet) and weights up to 50 kg (110 pounds).



SEA TURTLE SPECIES

Loggerhead Sea Turtle

     Grow up to 110 cm (3.5 feet)

Weight up to 170kg (375 lbs).

     Large head, reddish brown shell.


Slide 9 - Diapositive

Loggerhead sea turtles
Loggerhead sea turtles get their name from the shape of their head.  They have a large head and a reddish brown shell.  

They grow up to around 110 cm (3.5 feet) and weight around 170kg (375 pounds).


SEA TURTLE SPECIES

Leatherback Sea Turlte

Grow up to 183cm (6feet).

Weight up to 500kg (1,100lbs).

  Thin layer of tough skin over shell that gives it the appearance of leather.
  


Slide 10 - Diapositive

Leatherback sea turtles
Leatherback sea turtles have a thin layer of tough skin over the shell that gives it the appearance of leather.  They are the biggest of the sea turtles.  They grow up to around 183cm (6 feet) and weight up to 500kg (1,100 pounds).



SEA TURTLE SPECIES

Flatback Sea Turtle
   
    Grows up to 99cm (3.25 feet).

Weight up to 90kg (198 lbs).

Shell is flat compared to other turtles.

Slide 11 - Diapositive

Flatback sea turtles
These turtles get their name from the shape of their shell, which is flat compared to other sea turtles.  They grow to around 99cm (3.25 feet) and weight around 90kg (198 pounds).

Seven main species of sea turtle.
Hatchlings

Slide 12 - Diapositive

Hatchlings
During nesting season females will come ashore to lay eggs every couple of weeks. They use their flippers to dig a hole to lay the eggs in.  They can lay any number up to 200 eggs in a clutch.
After the eggs have been laid, the turtle fills the egg chamber with sand using her hind flippers, and then fills the body pit where she has been laying using all four flippers. So no one knows where she has laid her eggs.   
The sand filled chamber keeps the eggs warm until they hatch.  The temperature of the nest during this time determines whether the babies will be boys or girls. Warm, dark sand produces mostly females and cool, white sand results mostly in males.
It takes about 7 to 12 weeks for the eggs to hatch, but it then takes the babies (hatchlings) two or more days to reach the surface, usually at night, where they emerge as a group.

Seven main species of sea turtle.
What do sea turtles eat?

Slide 13 - Diapositive

What do sea turtles eat?
Young turtles spend their early years floating on the ocean current, so they tend to eat small sea creatures and algae.

Once they get older sea turtles move closer to shore.  The green sea turtle eats mainly sea grass, kelp and algae from the seabed, but will also eat other creatures, even the box jellyfish.

Other species will eat a mix of sea creatures like sea sponges, coral, sea worms starfish, shrimp/prawns, jellyfish and squid.

Seven main species of sea turtle.
Do sea turtles drink water?

Slide 14 - Diapositive

Do sea turtles drink water?
Sea turtles, like us, need to drink water, but because they drink seawater which is really salty they have a special gland that removes the salt from the water. It is located near their eyes and is like a tear duct that is constantly releasing salt out of their body.

Seven main species of sea turtle.
Breathing and diving.

Slide 15 - Diapositive

Breathing and diving
Sea turtles need to breathe oxygen to survive, but because they don’t have gills - like fish - they need to come to the surface to breathe.

Some species, like the green sea turtle, can submerge for up to 5 hours at a time, only coming to the surface for a few minutes to replenish oxygen. Others can only dive for shorter periods - like the hawksbill, which can dive for 45 minutes.

Seven main species of sea turtle.
Sea turtles are important to the ocean.

Slide 16 - Diapositive

Important to the ocean.
Sea turtles help to maintain the health and balance of coral reefs and sea grass beds, by eating some of the species that prey on coral reefs, such as sea sponges.  

Seven main species of sea turtle.
Predators.

Slide 17 - Diapositive

Predators
Sea turtles have a tough start to life. Hatchlings face a lot of hazards just trying to make it to the ocean and survive their first few years.  Many hatchlings fall prey to crabs and birds as they try to make their way to the sea.  

In the ocean hatchlings face threats from large fish and sharks, while adult turtles may fall prey to sharks, seals and orcas.


For turtle meat, eggs and
the shells to make ornaments.
Illegal poaching.

Slide 18 - Diapositive

Illegal poaching
The main reason sea turtles are disappearing from the ocean is because they are hunted by people, for the sea turtle meat, eggs and shells.

Female turtles come ashore in the nesting season, when they lay their eggs on beaches.  Sea turtles are slow moving and spend a lot of time digging a nest and laying eggs, then bury the eggs before heading back to sea. Poachers can wait until the eggs are laid before stealing them or taking the female turtle.

Female turtles use the same beach to nest on where they were born.
International laws regulate fishing.
Entangled in abandoned, lost or discarded fishing gear.

Slide 19 - Diapositive

Entanglement
Each year lots of fishing gear is lost or left behind in the ocean by fishing vessels.

These nets float in the ocean catching marine wildlife and can entangle sea turtles.  

Imagine sea turtles swimming along and all of a sudden they get caught in fishing nets and lines. They have to float all entangled until someone can help them, but not all of them find help in time.

Ask students how we can help stop the sea turtles becoming entangled?
  • By helping to clean up fishing gear from the ocean.
  • Making the fishing vessels clean up their own fishing gear properly.

Teacher’s note: Each year over 640,000 tonnes of fishing gear is lost, abandoned or discarded by the commercial fishing industry.

Taking eggs takes away the
next generation of sea turtles.
Plastic pollution - over 12 million tonnes of trash enters the ocean each year.

Slide 20 - Diapositive

A sea of plastic.
Every day all over the world rubbish is finding its way into the ocean.  It is thought that this rubbish amounts to more than one garbage truck every 40 seconds dumping trash in the ocean – imagine all that rubbish floating in the ocean

All kinds of trash is left behind at beaches or in waterways to be washed out to sea, dumped at sea from boats or lost from container ships in storms.

What do you think would happen if a sea turtle finds trash in the ocean?

Could they tell the difference between food and trash?

Teacher’s note: Over 12 million tonnes of trash is finding its way into the ocean each year.  This amount is growing each year.  It equates to one garbage truck every 40 seconds dumping in the once.

.




Stopping trash

How can we help stop trash reaching the ocean?


Slide 21 - Diapositive

How can we stop the trash?
Ask students: “What do you think we can do to stop this trash ending up in the ocean?”

Teacher’s note:
You can discuss things like:
    Reducing single use plastics.
    Using reusable products.
    How to properly dispose of rubbish.
    Recycling plastics.
    Doing clean ups. 


Female turtles use the same beach to nest on where they were born.
International laws regulate fishing.
Coastal development impacting nesting sea turtles.

Slide 22 - Diapositive

Coastal development impacting nests.
In many nesting areas the beaches have become popular places for people to live or tourists to visit.  People don’t take any notice of the sea turtles and will drive cars on beaches crushing the eggs in their nests or letting their dogs run loose on the beaches attacking the nesting sea turtles.

Ask students: “Think about beaches everyone goes to, busy with tourists. What things on the beach might stop hatchlings making it to the ocean?”

  • Leaving things on the beach – towels, rubbish, buckets – that the hatchlings have to climb over.
  • Leaving sand castles or sand piled up – make sure you flatten them when you leave.
  • Bright lights – did you know sea turtles follow the moonlight to find their way to the ocean? Which means if there are bright lights near by, the hatchlings could end up going the wrong way and get lost.


What do you like most
about sea turtles?

Slide 23 - Question ouverte

What do you like most about sea turtles?
Ask students to answer the following question using www.LessonUp.app or write on paper:  

 “What do you like most about sea turtles?”



Write down one issue that we talked about
that is harming sea turtles?

Slide 24 - Question ouverte

What is harming sea turtles?
Ask students to answer the following question using www.LessonUp.app or write on paper:

 “Write down one issue that we talked about that is harming sea turtles?”


Write down one thing that you can do to
help protect sea turtles?

Slide 25 - Question ouverte

How can we protect sea turtles?
Ask students to answer the following question using www.LessonUp.app or write on paper:
 
 “Write down one thing that you can do to help protect sea turtles?”



Write down one new thing you have learned today?

Slide 26 - Question ouverte

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

“Write down one new thing you have learned today?”


Write down one thing you didn't understand?

Slide 27 - Question ouverte

What don’t you understand?
Ask students to answer the following question using www.LessonUp.app or write on paper:

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


Slide 28 - Vidéo

Sea Shepherd Lesson Activity Sheets provide additional lesson activities or discussion topics to expand the learning experience.


Optional fun video.
Show this video (1.21 mins) which shows sea turtles:
https://youtu.be/UdXQFm33kvQ

www.seashepherdglobal.org

Slide 29 - Diapositive

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