Transcript 30.Ocean Zones & Layers

Ocean Zones & Layers
The ocean is divided into three zones across
and three layers down.
Use the diagram on the next slide to label
the diagram on your paper!
Intertidal
Zone
Neritic
Zone
Open Ocean Zone
Photosynthetic Layer
0-200m deep
Continental Shelf
Bathyal Layer
200-4000m deep
Continental Slope
Continental Rise
Abyssal Layer 4000m - ocean floor
The Crazy Zone: Intertidal
Zone
Crazy Environment: Water level
changes 4 times a day!
Organisms must deal with
extreme changes of:
• Temperature
• Drying out
• Different levels of water,
oxygen and light.
Intertidal Zone
• Tide Pools are an ecosystem in the Intertidal
•
Zone.
Biodiversity is very high in tide pools. There are
many different species in 1 small area.
Advantages of Living in a Tidepool
• Lots of O2 and sunlight
• Currents and tides mix
•
•
•
•
the water to take away
waste and bring in new
nutrients
Lots of nutrients
Rocks for shelter
There are few large
carnivores, so less
predators are there to
eat you
Rich food sources
Challenges of Living in a Tidepool
Desiccation = drying out.
• Organisms need to be able to
breathe in and out of water
How do you survive Tidepool
Living?
Olive Snail
• One way is to move between
tidepools, like hermit crabs do.
• Olive Snail: burrows into moist
sand.(Sand dollars, clams and
worms do this too)
• Limpet: Dig a hole in the rock –
traps water, and protects animal
from waves
Limpet
How do you survive tidepool
living?
• Use Cracks: Organisms
can crawl into these
protected areas. Protects
the animal from waves
and each other.
• Rockweed: This plant can
lose up to 90% water and
still survive!
Crab
How do you survive tide pool
living?
*Barnacles: Close their shells to reduce evaporation
*Sea Anemones: withdraws into itself and covers itself
with a thick outer skin
(http://www.youtube.com/watch?v=ctqvqES1PE8)
How do tidepool organisms deal
with extremes in temperature?
• Snails: have light colored
shells to reflect sunlight
and absorb less heat
• sea anemones:
Decrease the surface
area of their body (shrink
up) to decrease
evaporation of water
How do tidepool organisms deal
with Wave Action?
• Waves pound the shore
•
•
•
and can damage fragile
organisms.
Olive Snail: Buries into
sand
Barnacles: Clamp onto
rock, streamlined shape,
armored from wave
energy
Chiton: clings to rock with
suction cup/muscular foot
Deal with Wave Action…
•
Sea Star
Starfish: have suction cups to stick to rocks, but
they don’t work on sand
• Sea Palm: Plant that is flexible and streamlined,
so it can take the beating of waves.
Zone Two:
The Neritic Zone
• This is the area from the
shoreline to the edge of the
continental shelf.
Challenges in the Neritic Zone:
• Turbulent wave action
• Depths, temperature, etc. will
be affected by the tides.
• High levels of UV radiation
• Currents effect habitat
Neritic Zone
• Realize, the neritic
•
zone changes based
on the season, climate
& location.
This zone is influenced
by the land around it.
River run-off and
sediment cycles lead
to different amounts
of minerals in the
water.
The surface of the
ocean constantly has
access during the day
to sun, deeper areas
only receive sunlight
when the sun is
overhead.
• Animal life in the Neritic Zone:
Many different types, sizes, species.
Types of Animals in the
Neritic Zone
• Plankton = Floating animal
Plankton
(usually one to a few
cells)
• Nekton = Swimming,
Nekton
maneuvering animals
(fish, sharks, seals, etc.)
• Benthos = Bottom dweller
(on or in the ground)
Benthos (ex.
Halibut)
Zone 3: The Open Ocean Zone
• This is the rest of the ocean from the continental slope
out.
• Plants & Animals change a lot depending on what layer of
the open ocean they live in.
• Open Ocean Layers: Layers going down through
the depth of the ocean (Photosynthetic, Bathyl &
Abyssal)
Open Ocean ~ Photosynthetic
Layer:
• This is the top 200
meters of the ocean
across the entire
ocean.
• This is the area that
receives sunlight, so it
is the only area that
plants & algae can
exist.
Open Ocean ~ Photosynthetic Layer
Benefits to living here are:
• Warmer water
• Low pressure
• More nutrients, food and
plants.
Challenges are:
• More competition & danger
• Have to deal with water
movement (waves, tides &
currents)
• UV Radiation and some
temperature changes.
Open Ocean ~ Bathyal Layer:
• This is the area from
200 meters to 4000
meters deep.
• Light doesn’t reach
into this area, so
there are less animals
and NO plant life.
Open Ocean ~ Bathyl Layer
Benefits to living in the Bathyal Layer:
• Less competition
• Easier to hide in darkness from
predators
Challenges to living in the Bathyal Layer:
• It’s Dark!
• High pressure (increases with depth)
• Always very cold (but at least the
temperature is constant)
Open Ocean ~ Abyssal Layer:
• Area from 4000 meters to the
bottom, also known as “The
Deep”
• There is NO light here and
VERY few animals live here.
• These animals are WEIRD,
with strange adaptations to
living in such a cold, dark place
Open Ocean ~ The Abyssal
Layer
Benefits to living in the Abyss:
• Less predation & competition
(because not much lives here)
• Uniform temperature & salinity
Challenges to living in the Abyss:
•
•
•
•
Extreme pressure
Low nutrients
No light & cold temperatures
Low numbers of living things (so
finding a mate/food is hard)
Along the ocean floor we see these
land features:
• Abyssal Plains = Flat
sea floor
• Trench = A valley.
These are carved out by
water currents.
Ocean land features
• Mid-Ocean Ridge – in the middle of the ocean floor =
a continuous mountain range that winds around Earth
under the ocean waters.
On the ocean floor we also see
Hydrothermal Vents!
• HTV’s are cracks in the Earth’s crust
that spew hot water (up to 350 °F!).
• The water is heated by magma under
the sea floor.
• Only bacteria can live in this water.
• Interesting because the bacteria do
“chemosynthesis” by changing
sulfur in the hot water into food
energy (instead of photosynthesis,
which changes sunlight into food)