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Ocean Zones
Ocean Waters Contain Many
Environments.
 The Earth’s oceans can be divided into several different
regions:
 Estuary (Wetlands)
 Intertidal Zone
 Neritic Zone
 Open-Ocean (Oceanic) Zone
 Abyssal Zone
Estuary (Wetland)
 An estuary is a coastal inlet or bay where fresh water
from a river mixes with salt water from the ocean.
 The mix of fresh and salt water forms brackish water.
 Because an estuary is found at the mouth of a river, it
is easily collects all of the pollution that the river was
carrying. Estuary pollution is a major concern!
Estuary: Salt Marsh
 Most often found along
the coast from
Massachusetts to Florida.
 Examples of organisms
that live in a salt marsh:
 Mosquitoes
 Cord grass
 Crabs
 Shrimp
 Herons
 Egrets
Estuary: Mangrove Forest
 Most often found along
the tropical gulf water of
southern Florida
 Examples of organisms
living in the mangrove
forest:
 Mangrove tree- the
mangrove roots can
withstand most
hurricane winds.
The Intertidal Zone
 The intertidal zone stretches from the highest high-
tide line on land out to the lowest low-tide line in the
water.
 Organisms living in this zone must be able to:
 Tolerate the pounding of waves
 Tolerate changes in temperature
 Tolerate changes in salinity (saltiness of water)
 Live underwater and exposed to air
Intertidal: The Rocky Coast
 Examples of organisms
living on the rocky
coast:
 Black algae
 Rock lice
 Barnacles
 Rock weed
 Mussels
 Limpets
Intertidal: Tide Pool
 Examples of organisms
living in a tide pool:
 Sea stars
 Spiny purple sea urchin
 Sponges
 Sea anemones
The Neritic Zone
 The neritic zone is the part of the ocean that extends
from the low-tide line out to the edge of the
continental shelf.
 The neritic zone is the most diverse environment in
regards to plants and animals due to the available
sunlight and steady supply of nutrients.
 Upwelling currents cycle nutrients from the bottom of
the neritic zone to the surface.
Upwelling Currents
 Upwelling is the upward movement of cold water from
the oceans depths.
 Winds blow away the warm surface water, and cold
water rises to replace it.
Neritic: Kelp Forest
 Most often found in the
cold pacific water from
Alaska to Mexico.
 Examples of organisms
that live in the kelp
forest:
 Kelp
 Sea slugs
 Snails
 Sea otters
Neritic: Coral Reef
 Examples of organisms
living in a coral reef:
 Elkhorn coral
 Brain coral
 Star coral
 Octopi
 Spiny lobsters
 Shrimp
 Eels
 Many species of fish
The Oceanic Zone
 The Oceanic Zone (or Open Ocean) begins where the
neritic zone ends.
 Only a small portion of this zone receives sunlight.
 Dissolved nutrients are less abundant.
 The oceanic zone supports fewer organisms.
Open Ocean: The Surface Zone
 This zone extends as far
as sunlight reaches below
the surface.
 Examples of organisms
living in the surface zone:
 Algae
 Plankton
 Some species of fish
Open Ocean: The Deep Zone
 The deep zone is dark
and cold due to the lack
of sunlight.
 Few organisms can live in
this zone.
 Examples of organisms
that live in the deep zone:
 Angler fish
 Other species with
bioluminescent ability.
Abyssal Zone: Hydrothermal Vents
 A hydrothermal vent is
an area where ocean
water sinks through
cracks in the ocean floor,
is heated by magma, and
rises again.
 Examples of organisms
living around a
hydrothermal vent:
 Bacteria
 Red-tipped tube worms
Ocean Floor
 tallest mountains and deepest canyons
 Seafloor spreading – when tectonic plates move apart
(divergent plate movement) magma hardens and creates
more area on the ocean floor.
 Continental Shelf- flat or gently sloping land that lies
submerged around the edges of the continent. Found
between the shore line and the continental slope.
 Continental slope-The steep edge of the continental
shelf, marks true edge of continent
Ocean Floor
 Ocean Trenches-deep canyons. Some of Earth’s




deepest points. Mariana Trench
Abyssal Plain- wide flat area of the ocean floor
covered with sediment.
Mid-Ocean Ridge- chain of mountains.
Seamounts- Mountains whose peaks do not break the
surface of the ocean
Volcanic islands- mountains whose peaks break
the surface of the ocean, lava cools, islands
form.
 Draw a picture of the ocean floor from page 150-151 in
your textbook.
 Label the following:
 Continental shelf, continental slope, ocean
trenches, abyssal plain, mid-ocean ridge,
seamounts and volcanic islands.
Ocean Water Chemistry
 Salinity – is the measure of the amount of dissolved
salts. (NaCl + others…)
 Ocean’s salinity has remained constant but some areas
differ due to
 High temperature -  increase in salinity
 Very low temperatures  increase in salinity
 Near freshwater source  decrease in salinity
 Area with a lot of precipitation  decrease in salinity
Seawater contains many different
gases.
 Cold water holds more gas than warm water.
 Seawater with low salinity holds more gas than high
salinity water.
 Deep water, which has a high pressure, holds more gas
than shallow water.
Ocean water Chemistry
 DENSITY

Salt water is more dense than fresh water
Oceans Layers
 Surface Layer- heated by the sun and mixed up
with waves. Remember heated water is less dense
so it stays at the surface. (0-200 meters deep)
 Thermocline/ Transition- lies below surface
water and is colder as you go deeper. (200 m – 1km
deep)
 Deep Water- cold all year. Barely above freezing
all year in all places. (1km – ocean floor)
 Near the Equator the ocean water is always warmer
at the surface.
Exploring the Water Column
ZONE
DEPTH
TEMP. PRESSURE
DENSITY
SALINITY
Color &
light
Surface
Zone
Surface
to 200m
deep
17.5 C
Least
pressure
Least
dense
(warm)
Varies
Yellow to
blue
green
Transition 200m to
Zone
1,000m
deep
4C
Increase in
pressure
Increase in Constant
density
Deep
Zone
3.5 C
Greatest
Most
pressure 400x dense
atm. pressure
1,000m
(1km) to
ocean
floor
Constant
No light
No light
Oceanography
 -the study and exploration of the world’s oceans.
 Oceanographer- scientist who studies the ocean.
 Marine biology- study of saltwater ecosystems and
estuaries
 Fishery biologist-manage specific fish populations
(game fish)
How do we study what we can not see?
 Remote Sensing: Collecting data when not
physically there
Go to http://sharks-ocearch.verite.com
 SONAR – SOund NAvigation Ranging use to measure
ocean depth
 The key is to know how fast the sound waves travels
through salt water!
Submersibles and ROV
small submarine equipped
with windows, lights,
mechanical arms, cameras
and other scientific
instruments able to
withstand the water
pressure
Remotely Operated
Vechicle - ROV
Satellite Imagery- Used to
 see Algal Blooms
 identify amounts and locations of phytoplankton
 Monitor ocean temperatures (El Nino –p139-140 blue
book)
Buoys- monitor temperature, winds, and currents
Abiotic vs. Biotic
 Abiotic –
nonliving parts
of an
ecosystem
 Biotic – living
parts of an
ecosystem
Abiotic Ocean Factors
 Salinity
 Gases : oxygen, nitrogen, carbon dioxide
 Temperature
 Density
 Nutrients and oxygen (do to upwelling and downwelling)
 Color/Light
 Depth
 Pressure
 Ocean floor
Marine Organisms classified into
three main groups
 Benthos- organisms
that live in, on or at the
bottom of the ocean
 Examples- starfish,
sponges, snails and
tubeworms
Plankton
 small microscopic
organisms that move
with the currents
 Bottom of the food chain
in the ocean
 Phytoplankton-
producer
 Zooplankton- primary
consumer
Nekton
 swimming animals that
can move independently
of the current
Food Web- show the interconnected network of the food chain within an ecosystem.
Is this Aquatic, Terrestrial, or Both?
Energy Pyramid
 Shows the amount of
energy that moves from
one feeding level
(trophic level) to
another.
 Each level has less
energy than the level
below
 10 % of the energy at one
level of a food web is
transferred to the next
higher level.
Energy Pyramid
 Energy is measured in
kilocalories (kcal)
 The most energy is at the
producer level.
 As you move up the
pyramid level, each level
has les energy available
 As a result fewer
organisms at highest
level
Design an energy pyramid of an ocean
ecosystem
 Give the pyramid a title
 Include producers,1st order consumers, 2nd order
consumers, 3rd order consumers
 Label trophic levels and producers/consumer
 Record energy transferred at each level in kilocalories
(kcal)
 Summarize the flow of energy under your
pyramid(five sentences)!