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Earth Systems, Structures and
Processes
8.E.1.2
Summarize evidence that Earth’s oceans are a
reservoir of nutrients, minerals, dissolved
gases, and life forms:
•Estuaries
•Marine ecosystems
•Upwelling
•Behavior of gases in the marine environment
•Deep ocean technology and understandings
gained
Earth’s Oceans
More than 70% of the Earth’s surface is
covered by ocean water.
Most of the ocean floor has not been
explored because it is so vast and deep.
There are many similarities in features
between the ocean floor and land.
One Ocean
• Earth’s oceans are often split into 5 different
ones:
–
–
–
–
–
Atlantic
Pacific
Indian
Southern
Arctic
• There is actually only one continuous ocean
One Ocean
• Ocean Basin
– Part of Earth’s surface that is covered by
ocean water.
• Pacific is largest and deepest
• Arctic is coldest and shallowest
– Mostly covered in ice
Ocean Floor
• Ocean floor includes
– Continental shelf
– Continental slope
– Mid-ocean ridge
– Rift valleys
– Trenches
Ocean Floor
• Most of the ocean is dark, flat area called
the Abyssal plain
• Ocean trench is a large V-shaped valley
• Mid-ocean ridges are underwater
mountain ranges
– Some of the mountain ranges reach above
the water to form islands.
• Ocean floor mapping video
Ocean Composition
• Most of the Earth’s water is not drinkable
(potable) because of the salt.
– Why can’t we drink salt water?
• Even though the ocean is fed by fresh
water, because of the salt left behind in
evaporation, the fresh water quickly
becomes salty.
• Underwater volcanoes also add salt.
– Why is ocean water salty?
Ocean Composition
• Salinity
– The saltiness of a body of water
– In an ocean, it averages about 3.5%
• This means that about 3-4% of the water is made up of
dissolved salt
• Rather than H O only for the water, it is actually:
2
– H O with about 3-4% NaCl
2
– Salinity levels are lower where fresh water flows into
the ocean and higher where there is a greater rate of
evaporation
• Such as near the Equator
Ocean as a Resource
• The ocean has been used as a source of food for
centuries.
– Fishing is a major industry in North Carolina
• Swordfish
• Tuna
• Flounder
• Shrimp
• Crab
• Oysters
• Scallops
Ocean as a Resource
• Food resources are often threatened by
pollution
– The release of an unwanted substance into
the environment
– Oil spills
• Taking too many resources before they
can reproduces is called Overfishing
• Sustainable Resources
Marine Ecosystems and Estuaries
• Almost half of the known species on Earth
live in the ocean
– That number could be greater due to the vast
unknown of the ocean depths
– Ocean Depths
The Ocean’s Producers
• Marine (Ocean) producers are important
to all life on Earth
• Main producers are algae and
phytoplankton
– They live in the upper regions of the ocean
and get enough light for photosynthesis
• Light can not reach deeper into the ocean so there
are no producers at deeper levels.
– Marine food web
The Ocean’s Producers
• Marine Organisms
– Benthos
• The flora and fauna found on the bottom, or in the bottom
sediments, of a sea, lake, or other body of water.
– Nekton
• Aquatic animals that are able to swim and move
independently of water currents
– Plankton
• Microscopic organisms that float freely with oceanic currents
and in other bodies of water.
• Plankton is made up of tiny plants (called phytoplankton)
and tiny animals (called zooplankton).
The Ocean’s Producers
• Populations of producers can be affected by ocean
currents
– Oceanic currents describe the movement of water from one
location to another.
– Ocean currents are driven by wind, water density differences,
and tides.
– Ocean currents can cause Upwellings
• Carries cold water from the deep in the ocean up the surface
• Winds blowing across the ocean surface push water away. Water
then rises up from beneath the surface to replace the water that
was pushed away. Upwelling occurs in the open ocean and along
coastlines.
– This water is rich in nutrients from the ocean floor
– Producers use the nutrients to increase populations
Marine Ecosystems
• There are three major ecosystems
– The Shore
– The Open Ocean
– The Deep Ocean
– Really annoying but very informative video!
Marine Ecosystems
• The Shore
– The part of the ocean nearest the land
– With shallow water, light can reach the
bottom of the ocean
– Waves create a lot of motion in this area
moving sand and mud
– This creates Sediment deposits
• Naturally occurring material that is broken down by
processes of weathering and erosion, and is transported by
the action of wind, water, or ice until deposited through
gravity.
– Tides rise and fall and some creatures thrive
such as clams, mussels and worms
Marine Ecosystems
• Photic Zone
– Surface layer of the ocean that receives
sunlight.
• Euphotic Zone
– The uppermost 80 m (260 feet) or more of the ocean,
which is sufficiently illuminated to permit photosynthesis
by phytoplankton and plants.
• Ocean Photic Zones Video
– (Volume may need to be raised)
Marine Ecosystems
• The Open Ocean
– The vast area of top ocean level that expands
from shore to shore
– This expands as deep as light is allowed to
filter down
• The sun warms the water at these depths
– Light is bright enough for photosynthesis
– Some of the organisms that thrive here are
jellyfish, fish and squid
Marine Ecosystems
• The Deep Ocean
– Thousands of meters below the ocean’s
surface
• The water is very cold
– Openings in the ocean floor release heat called
Hydrothermal Vents
– Small ecosystems exist around these vents
– They rely on organisms called autotrophs that make their
own food No light filters down so photosynthesis can not
take place
– Because of this, Chemosynthesis takes place
 Process
of using energy stored in chemical bonds
instead of sunlight to produce food
Ocean Acifidication
• Ocean acidification is the ongoing
•
decrease in the pH of the Earth's oceans,
caused by the uptake of carbon
dioxide (CO2) from the atmosphere.
Carbonic Acid
– A chemical compound with the chemical
formula H2CO3
– It is also a name sometimes given to solutions
of carbon dioxide in water, because such
solutions contain small amounts of H2CO3
– Contributes to the increase in the ocean’s pH
Estuaries
• Estuary
– A body of water in which freshwater from a
river meets and mixes with salt water from
the ocean
– Known as inlets, bays, harbors, lagoons and
sounds
• Examples are Boston Harbor, Chesapeake Bay,
Pamlico Sound, and Albemarle Sound
– Salinity levels change based upon tides, wind
direction and storms
Estuaries
• Often protected from ocean waves by land
features.
– Barrier Islands, Reefs, Sand spits
– Rich in nutrients, dissolved oxygen, and
minerals
– Can be used a nurseries for many animals
including some ocean animals that come to
breed
• Reservoir
– A large natural or artificial lake used as a
source of water supply.
Neuse River
• Kayaking
• Lower Neuse River 1
• Lower Neuse River 2
• Rachel Carson Reserve