The World’s OceansThe World’s OceansAnd who lives there…

The OceanThe Ocean

• Divided into three zones:

• Sunlight

• Twilight

• Midnight

• Can you guess which one is the darkest?

SUNLIGHT ZONESUNLIGHT ZONE

• Top layer, nearest the surface

• Also called euphotic zone

• Enough light penetrating the water for photosynthesis

• More than 90% of all marine life

lives here

SUNLIGHT ZONESUNLIGHT ZONE

• Goes down about 600 ft.

• Most fish live in this zone– (Stingrays, seals, jellyfish, turtles)

• Plankton live here. – Plankton are drifters…they can’t swim.– Usually microscopic – Beginning of the food chain 

PLANKTONPLANKTON

• Examples are:

• Jellyfish

• Young crabs

• Microscopic plants

• Microscopic animals

TWILIGHT ZONETWILIGHT ZONE

• Small amount of light can penetrate water

• No plants

• Only those that have adapted

to little light 

• Also known as disphotic zone.

TWILIGHT ZONETWILIGHT ZONE

• Between 600 – 3,000 feet below the surface

• Some squid and fish can use their bodies to make light

• Bioluminescence

• They Glow!

TWILIGHT ZONETWILIGHT ZONE

• Some twilight zone dwellers

(like lantern fish)

will swim into the sunlight zone

at night to find food.

MIDNIGHT ZONEMIDNIGHT ZONE

• 90% of the ocean

• Entirely dark—no light

• Temperature is near freezing

• Also called aphotic zone

MIDNIGHT ZONEMIDNIGHT ZONE

• What lives here?

• Some are close to cracks in the Earth's crust

• Cracks give off mineral-rich materials

• Bacteria uses minerals from the cracks for energy

• All other living things in the midnight zone are nourished by these bacteria.

Let’s Tour The DeepLet’s Tour The Deep

• Click “Worlds Within the Sea”

• Click “Deep See Vents”