Ocean Zones, Ocean Life,
and Ocean Chemistry
Ocean Zones
Beach
Shallow Ocean
Intertidal Zone
Neritic Zone
Continental shelf
Continental Slope
Deep Ocean
Open-Ocean Zone
Surface Zone
Middle/Transition Zone
Deep Zone
Abyssal Plain
There are 3 horizontal ocean zones:
Intertidal Zone- area at the seashore that is underwater during high-tide and exposed during low-tide
Neritic Zone- extends from the low-tide line to the edge of the continental shelf
Open-Ocean Zone- ocean beyond the edge of the continental shelf
There are 3 vertical ocean zones:
Surface Zone- sunlit area where plankton live and zone whose temperature is most affected by weather
Middle/Transition- zone in which most of the ocean’s nekton (free-swimming organisms) live
Deep Zone- deepest, darkest, coldest zone where most organisms are benthic (bottom-dwellers)
Ocean Zones
Shallow Ocean
1.
Deep Ocean
2.
5.
6.
7.
8.
10.
11.
9.
12.
Abyssal Plain
Neritic Zone
Continental Shelf
Intertidal Zone
Low-Tide Line
Surface Zone
Transition Zone
Deep Zone
Beach
Continental Slope
Open-Ocean Zone
High-Tide Line
Three Groups of Marine Life
Plankton
Nekton
Benthos
Check What You THINK You Know
plankton, nekton, benthos
• What life zone do you think this lives in?
• What life zone do you think this lives in?
• What life zone do you think these live in?
Check What You THINK You Know
plankton, nekton, benthos
• Which type of organism do you think lives
on the ocean floor?
• Which type of organism do you think
swims freely throughout the ocean?
• Which type of organism do you think lives
on the surface of the ocean?
PLANKTON and ALGAE
• The majority of plankton and algae are microscopic.
• They float on the surface on the ocean where there is
plenty of sunlight.
• Like algae and any other plant, they need carbon dioxide
to breathe and sunlight to undergo photosynthesis.
• They create a lot of oxygen when they breathe, so much
that there is 60 times as much oxygen in the ocean as
there is in the atmosphere.
PLANKTON
• There are two types of plankton.
• Phytoplankton are plant-like organisms.
• Zooplankton are animal-like organisms.
NEKTON
• Nekton are free-swimming organisms.
• They are the majority of organisms that
you probably think of when you hear
“marine life.” They are very abundant in
the ocean.
NEKTON
• Nekton organisms have the ability to swim
freely throughout the main body of the
ocean.
NEKTON
• There are many types of nekton.
BENTHOS
• Benthos are organisms that live on or in
the ocean floor.
• They live in the mud, sand and rock that is
found on the ocean floor.
• Many benthos organisms are probably
very familiar to you.
BENTHOS
• There are many different types of benthos
organisms.
The Ocean Food Chain
• Plankton
Plankton are at the bottom of the food chain. Zooplankton eat
the phytoplankton.
• Nekton/Benthos
Certain members of the nekton eat plankton and they eat each
other. Usually the bigger organisms eat the smaller ones, like a
shark eating smaller fish, but this is not always the case.
Certain types of whales called baleen whales don’t eat fish.
They eat only plankton. These filter feeders take in large
amounts of seawater as they swim and filter out the plankton
for food.
• Benthos
Benthos must protect themselves from predators and create
sheltered homes.
The Ocean Food Chain
http://magma.nationalgeographic.com/ngexplorer/0309/quickflicks/
Let’s see what you have REALLY
learned!
I am going to show you some pictures.
You need to identify which life zone that
animal lives in!
Benthos--------Plankton--------Nekton
What else have you learned?
• Which type of organism lives in the main body of
the ocean?
• Which type of organism needs to create safe
shelters on the ocean floor for protection?
• Which type of organism has only two types?
Benthos-----------Plankton----------Nekton
Ocean Chemistry
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Salinity = Salt (NaCl-Sodium Chloride)
Higher Temperature = More Evaporation
More Evaporation = Saltier Water
Lower Temperature = Less Evaporation
Less Evaporation = Less Salty Water
Where is the water more salty? ___ Less salty? ___
A. Off the coast of Antarctica
B. Off the coast of Florida
Ocean Chemistry
The Atlantic Ocean experiences more evaporation than the
Pacific Ocean therefore the water in the Atlantic Ocean is:
A. Less salty
B. More salty
and therefore the average temperature of the Pacific Ocean
must be:
A. Lower
B. Higher
than the Atlantic Ocean.
Even though many gallons of freshwater pour into the oceans each day,
the salinity (saltiness) of the ocean remains in balance at about 35 parts
per thousand (35/oo) because water is constantly evaporating from the
ocean, leaving the salt behind.
Your Turn!
HOMEWORK
• Each pair member choose 1 of your organisms.
• Draw the organism you choose and color it.
The End