The document describes the three main zones of the ocean - the Sunlight Zone, Twilight Zone, and Midnight Zone. It notes that over 70% of the Earth's surface is covered by oceans, making water vital for life. The deeper zones have higher pressure, colder temperatures, and less light. While the Sunlight Zone extends from the surface to 300 feet and receives the most sunlight, hosting 90% of ocean life, the midnight zone extends from 3,000 feet down and has very little life in its dark, freezing, high-pressure environment. Bioluminescence is described as light produced by living organisms, commonly used by twilight zone fish for hunting, communication, and other purposes.

1. Our Big Blue Marble
The Oceans

2. We call it the Big Blue Marble.
⚫Why?

3. Some basic facts!!
⚫Yes, the Earth is covered in water!
⚫And where is most of that water?
⚫YES! In the oceans. In fact, over 70% of the Earth’s
surface is liquid – the oceans!!
⚫Why is this important for our planet?
⚫As we have discussed, liquid water is the most
important factor in developing life on this planet. We
are the only planet that has it. Without it, we’ve got
nothing!!

4. Just like going to deep space!!
⚫The ocean is a fascinating place.
⚫In many ways, exploring it is just like exploring space.
In fact, many scientists have said that exploring the
deepest parts of the ocean is more difficult than
exploring deep into space.
⚫Any idea why?
⚫The deeper into the ocean you go, the more punishing
the oceans can be . . . . .

5. Rollin’ in the deep . . . .
⚫The deeper you go, the more difficult and punishing an
environment the ocean is.
⚫First, the deeper you go, the darker it gets.
⚫When you reach the bottom, guess what?
⚫It’s DARK! No light penetrates to the deep ocean floor.
⚫And the deeper you go, the more the ocean attempts to
crush you!
⚫Water pressure!! At sea level, your body experiences
about 14.7 pounds per square inch of pressure. In the
ocean deep, that pressure is about 8 tons per square inch!
⚫Also, the water gets colder the deeper you go!!

6. Cakes, Shrek, Onions, Parfait, and the Oceans!
⚫What do all of these things have in common?
⚫Yes! LAYERS! They all have layers!
⚫The ocean is divided into layers, or zones, that are
marked by depth.
⚫The Sunlight Zone (0 - 300 feet)
⚫The Twilight Zone (301 – 3000 feet)
⚫The Midnight Zone (3001 – abyss)
⚫Why do you think they have those names?

7. The Zones!

8. The Sunlight Zone
⚫Fill in the blank . . . . The sunlight zone is the zone in
the ocean that gets the most _________________.
⚫Okay . . . Swimmers would work as an answer, but
SUNLIGHT would be the winner!
⚫The sunlight zone extends from sea level down to
about 300 feet and the water is a beautiful light blue.
⚫About 90% percent of all fish in the oceans live in the
sunlight zone? Why?
⚫Sure – it’s the easiest place to live! Water
temperatures are warmer, there’s more plant life, etc!

9. Take me to the Sunlight Zone!

10. . . . . And again . . . . . . . . . .

11. . . . . . . . . . . And again . . . . . . .

12. . . . . . . . . . . And again . . . . . . .

13. You are about to enter The Twilight Zone!
⚫Okay, not THAT Twilight Zone!

14. The Twilight Zone
⚫As you leave the sunlight zone at around 300 feet, you
will enter the twilight zone.
⚫Will there be more or less light in the twilight zone?
⚫Yes, LESS light. The deeper you go, the less light
there will be! Also, the more water pressure you will
experience you will feel! And the colder the water will
be!

15. THIS Twilight Zone!
⚫As you head into the twilight zone, you’ll notice a
number of things.
⚫First – the water appears to be a darker blue because
there is less . . . . . . . LIGHT!
⚫Second – the water is getting colder because there is
less . . . . . . . . . LIGHT!
⚫Third – the water pressure is doing its best to squash
you like an empty soda can!

16. Living in the Twilight Zone!
⚫You will also find less life in the twilight zone than in
the sunlight zone.
⚫Why?
⚫Sure, because there is less light and the water is
colder. Neither one of those factors make living
easier!
⚫Less plant life/plankton to feed on means fewer fish!
⚫Many fish that live in the twilight zone actually feed
on stuff that sinks into this zone from the sunlight
zone. Others will go up into the sunlight zone to
hunt.

17. Cool party trick!!!

18. Bioluminescence!
⚫This is a fancy Greek word meaning “light from life.”
⚫Many fish in the twilight zone can do this.
⚫These fish have many reasons for doing this. Can you
think of any?
⚫Sure – to hunt, just like the angler in Finding Nemo.
⚫To communicate.
⚫To confuse predators.
⚫To find mates.
⚫Typically, this light is a bluish green, but some animals
actually create a red light.

19. Some very cool light from life!

20. Look at the pretty fishy!!

21. Want one of these for your tank?

22. The Midnight Zone
⚫Interesting fact – 90% of the ocean is in the midnight
zone!
⚫The water is near freezing!
⚫The water pressure is crushing!
⚫The water is pitch black.
⚫Of the three zones, life is most difficult down here.
Very little fish, no plants . . . . .
⚫Much of life in the midnight zone lives near the
cracks in the ocean floor that release heat and
minerals into the water.

23. It’s an alien world down there!

24. Oooh, Mommy! I want one!

25. Here lil’ squishy!!

26. Were you paying attention?
⚫What is the top layer of the ocean called?
⚫What is the middle layer of the ocean called?
⚫What is the bottom layer of the ocean called?
⚫What is true about the water pressure at the bottom
of the ocean?
⚫How much light is at the bottom of the ocean?
⚫What does bioluminescence mean?
⚫In what zone do most fish live?