Transcript Oceans 11 - Unama'ki Training & Education Centre

Oceans 11
Module 1:
Ocean Structure & Motion
The World Ocean
Video: Map of Oceans
What is meant by the term “world
ocean”?
• The world ocean is a great body of water
that surrounds the continents of the Earth.
All of the “oceans” are interconnected.
• The world ocean is often divided into
subdivisions that we call “oceans “.
• There are five oceans: Atlantic, Pacific,
Indian, Arctic & Southern
Facts About the World Ocean
• Oceans cover over 71% (or almost ¾) of the Earth’s
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surface (which amounts to 361 million square km)
The Pacific is the largest ocean and covers about 1/3 of the
Earth
There is more ocean in the Southern Hemisphere
The word ocean comes from Oceanus, one of the Greek
Titans
The average depth is about 4000 metres (sort of like a
damp basketball
The deepest point in the ocean is Challenger Deep in the
Mariana Trench at 11,035 metres
Mariana Trench…verrryyy deep!
Apple Ocean Activity
How do you think the ocean
is like an apple?
Oceans Volume Activity
• How much seawater is on Earth?
What is meant by the term
“sustainability”?
Overview of the Ocean Sub-Basins
1. Characteristics of the Atlantic Ocean:
• Long & narrow; S-shaped
• Very few islands
• Mid-Atlantic Ridge extends down the
middle of the Atlantic like a spine; lots of
volcanic activity here
• Lots of rivers
• Large continental shelves
2. Characteristics of the Pacific Ocean:
• Total area of the Pacific equals Atlantic +
Indian Oceans
• Lots of islands
• Few major rivers
• Great deal of volcanic activity
(Pacific Ring of Fire)
• Lots of deep trenches near continents
3. Characteristics of the Indian Ocean:
• Smallest ocean
• Few developed nations
• Very few islands
4. Characteristics of the Arctic Ocean:
• Ice covered
• Almost land-locked
• Large continental shelf
• Very COLD!!
5. Characteristics of the Southern Ocean:
• Surrounds the ice covered continent of
Antarctica
• Named in 2000
Ocean Fact Finder Challenge
• Complete the handout and submit as
Assignment #1 on the due date
Our Ocean Neighbourhood
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Can you locate some
of the following features:
Bras d’Or Lake
Sydney Bight
Sydney Harbour (an estaury)
Cabot Strait
Gulf of St. Lawrence
Sable Island
Grand Banks
Georges Bank
Bay of Fundy
Gulf of Maine
Labrador Current
Gulf Stream
Plate Tectonics
• Complete the anticipation guide and watch
the following video
• Then, review your answers and make any
necessary changes.
• Video
How did the different oceans form?
• The oceans formed when the huge
supercontinent of Pangea broke apart
• The result were a number of ocean subbasins and continents, all of which are
sitting on plates.
Pangea Animation
Video
What is plate tectonics?
Plate Tectonics is the study of the origin and
arrangement of the broad physical features of
the Earth.
Plate tectonics is the basic idea that the Earth is
divided into a few large plates that move slowly
and change in size.
Intense geological activity (earthquakes,
volcanoes, mountain building) occur where the
plates meet. Where the plates meet are called
plate boundaries. Plates can move toward
each other, away from each other or slip past
one another.
Videos
• Plate tectonics
• Sea floor spreading
Model of Mantle Convection
Major Plates of the Earth
Plate Boundaries
There are three types of plate boundaries
1. Divergent (or constructive) plate
boundary
2. Convergent (or destructive) plate
boundary
3. Transform (or slip & slide) plate
boundary
Divergent Plate Boundary
Divergent Plate Boundary
• This happens when two plates separate
and magma (liquid rock) flows from the
crust to form new mountains
• Example: Mid- Atlantic Ridge
Divergent Plate Boundary
• Mid-ocean ridges are formed when plates
move apart. They are giant undersea
mountain ranges that extend around the
world.
• Earthquakes & eruptions of rock are
frequent along the ridges. Iceland formed
atop a ridge.
• Exotic creatures often live along ridges.
Convergent Plate Boundaries
Convergent Plate Boundaries
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With convergent plate boundaries, plates move toward
each other
There are three possible collisions:
Oceanic crust colliding with oceanic crust causes one
to dive under the other (often forming deep trenches
or island chains)
Heavier, denser and thinner oceanic crust colliding
with the continental crust causes the oceanic crust to
dive (often forming deep trenches)
Two colliding continental crusts cause crumpling &
mountain building (ex. Himalayas & Mt. Everest;
Appalachians of Eastern North America, including the
mountains of Eskasoni)
Transform Boundaries
• With transform boundaries, one plate
slides horizontally past another plate
• The result is often a fault or massive
“crack” in the Earth’s crust (ex. San
Andreas fault in California; Aspy Fault in
C.B. Highlands)
• Earthquakes are very common (and often
violent) along transform boundaries
San Andreas Fault
Video
Transform Boundaries
Major Plates of the World
Oceans Quiz #1
1. What is meant by the term “world
ocean”?
2. Name five oceans.
3. Name one type of plate boundary.
Common Physical Features of
the Ocean Floor
Beach & shoreline
Land
Seamount
Continental
shelf
Trenches
Continental
Ridges
slope
Continental
rise
Abyssal
plain
Common Physical Features of
the Ocean Floor
Land
Beach & shoreline
Continental
shelf
Continental
slope
Continental
rise
Ridges
Seamount
Abyssal
plain
Trenches
Common Physical Features of
the Ocean Floor
• Continental shelf:
These are the shallow parts of the sea
floor next to the land. The slope is about
2m per km; avg. depth is 130 m; avg
width is 70 km (up to 1000km)
• Continental slope:
This occurs at the end of the continental
shelf. The slope is greater (70m/km) and
in some places drops 3600 metres down.
• Continental rise:
The continental slope ends here. The
continental rise slopes very slowly here.
The rise can be wide (up to 1000km), and
has huge amounts of sediments.
• Sea floor (abyssal plain):
The sea floor is the flattest area on Earth.
It covers about 42% of the Earth’s
surface. The floor may have trenches or
canyons.
• Seamount:
A seamount is an isolated or stand-alone
mountain. Some become islands such as
Hawaii and the Midway Islands.
Island of Surtsey, born 1963
Nishino-shima volcanic island;
Born Nov 20, 2013
Seamount Formation
Seamount
Guyots
A guyot is a seamount with a flattened top
Emperor & Hawaiian Seamounts
• Atoll:
An atoll is a round, donut shaped island
built on coral. Ex. Bikini Atoll
Trenches
• Marianas Trench video
How do you measure the depth
of the oceans?
Measuring Bathymetry
There are several ways to measure bathymetry
(or the depth of the ocean):
1. Plumb lines - lines suspended from ships
2. Sonar – sound waves are bounced off the bottom
3. Satellites – satellites (ex. SEASAT) measures small
differences in the height of the sea surface
4. Lasers – planes use laser beams that bounce off the
ocean bottom
5. Mulitbeam sonar – several sonar beams are used to
create a highly detailed map of the ocean bottom
Sonar
Satellites
Ocean bottom mapped by SEASAT
Multibeam sonar
Image of part of the Bras d’Or Lakes
mapped using multibeam sonar
Bathymetry of The Bras d’Or Lakes
Lasers (from aircraft)
Reading Activity: Lasers and Post-Superstorm Sandy
All About Water (H2O)
Introductory Video
Physical states of matter
Elements in Seawater
• The two most important parts of seawater
are:
1. Water (H2O) –> 96.5%
2. Salt (NaCl) –> 3.5%
• Other parts of seawater include dissolved
oxygen (O2), carbon dioxide (CO2),
nitrogen (N) and other dissolved chemicals
• Interesting fact: In seawater, there is
0.00005 grams of gold per ton of
seawater. So, the total amount of gold in
the ocean is about 9 million tons!!!
List of all elements in seawater:
Universal Solvent
• Water has been described as the universal
solvent. Just like a sugar cube dissolving
in water, many substances dissolve easily
in water. The elements in seawater come
from land runoff, cosmic dust and the
atmosphere.
Measuring Salinity
• Salinity is the measure of the amount of
salt in water.
• Salinity is measured in a unit called parts
per thousand or ppt
• Average seawater has a salinty of 35 ppt.
This would mean that 1000 grams (or 1
litre) of seawater has about 35 grams of
salt. This is about 1.5 tablespoons per
litre of water.
• The salinity of ocean water in the
open ocean away from land is 35 ppt
or 35‰
• Salinity of East Bay is low – 21 ppt
• Salinity of Seal Island – 29 ppt
A Little About Density
• The term density refers to the mass of a
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substance per unit volume (or the amount of
stuff). Helium would have a low density, wood
would have a medium density and iron would
have a high density.
Pure water (at 3.98°C) has a density of exactly 1
gram per cubic centimetre (1 g/cm3)
If a substance has a density of less that 1
g/cm3, it will float
If a substance has a density greater than 1
g/cm3, it sinks
Demo
• Density Demonstration
Pop Quiz
______ & _______ water floats, while
______ & _______ water sinks!!
Word Bank:
fresh
salty
cold
warm
Freshwater vs Saltwater
• Freshwater has a density of close to
1 g/cm3. Saltwater is heavier with a
density of 1.035 g/cm3
• Therefore, when saltwater and freshwater
mix, the saltier water sinks and the fresher
water floats
• Density is also affected by temperature.
Warm air rises, cold air sinks. Warmer, less
dense water rises while colder, more dense
water sinks
Resources
• Theromohaline Circulation
• Great Demo!!
What is thermohaline circulation?
• “Thermo” refers to temperature while
“haline” refers to salt. So, thermohaline
circulation is about ocean circulation that
involves water temperature and salt
content.
What does thermohaline circulation
mean?
• Cold, salty water sinks to the bottom of
the ocean. Warm, less salty water stays
at the top of the ocean.
• Cold, salty water at the poles sinks to the
ocean bottom. Eventually, this water
makes its way to the surface near the
equator. This warm water is pushed back
to the Poles with the help of winds.
Conveyor Belt???
What is the “Global Conveyor Belt”
and why is it important?
• The Global Conveyor Belt moves cold
water away from the Poles and warm
water back to the Poles. Currents act like
a conveyor belt to transfer heat to the
Poles. Therefore, the Poles (and Nova
Scotia) never get super cold, and the
Equator (near Brazil) never gets super hot.
• Read article & answer questions
Major Surface Currents
Oceans in
Motion
Video
Facts about surface currents:
• There can be cold currents (ex. Labrador
Current) or warm (ex. Gulf Stream)
• They can be fast moving
• They spin clockwise in the Northern
Hemisphere (in NS) and counter-clockwise
in the Southern Hemisphere (in Australia)
• What causes this spin?
Answer: Coriolis Force
What are currents?
• Currents are like rivers in the ocean.
• There are three main factors that cause currents:
1. Heat energy from the sun causes winds which
push on the surface of the ocean
2. Heat energy from the Sun causes density
changes. So, warm water rises, cold water sinks,
salty
3. rotation of the Earth
• Deep water currents carry cold water away from the
poles, while surface currents carry warm water to
the poles.
Global Warming & Global Currents
• Some people think that 250 million years
ago, global warming caused a malfunction
of the global conveyor belt.
• This may have lead to the extinction of
90% of all life on Earth.
• Is this gradually happening now? Maybe.
What is the Coriolis force?
• Simply put, it affects everything that moves
through the air (and currents in the ocean), and
it makes everything turn a little bit. When you
look at a satellite picture of the Earth you see all
these storms and clouds swirling around.
Objects normally move in a straight line when
you're on a non-spinning world. However, in a
spinning world, if you move in a straight line,
you really wind up curving and never get to the
place you want to go.
BBC Video
Merry-Go-Round Video
Science Museum of Virginia, Richmond, VA, USA
What is the real world effect of the
Coriolis Force?
• In the Northern Hemisphere, weather
patterns (such as hurricanes) and oceanic
currents tend to rotate in a clockwise
pattern. This is called the North Atlantic
Gyre off of NS.
• In the Southern Hemisphere, the rotation
is counter-clockwise.
The Gulf Stream
Facts About the Gulf Stream
• The Gulf Stream was discovered by Benjamin
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Franklin in 1769 or 1770
Max. speed is 16.6 km/h which occurs off the
coast of Miami
Max. volume is 90 million cubic metres (or
“bathtubs”)
Once described as a “river in the ocean”
The Gulf Stream carries warm water from the
Gulf of Mexico to northern waters. This is why
people swim in Sweden in the summer!
Video
Warm Core Rings
Cold Core Rings
• Warm core rings are “bubbles” that pinch off from
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the Gulf Stream. The water in these rings is warmer
than the surrounding water.
They slowly spin clockwise at about
3 km/h
They are raised from the sea surface by about 50cm
They last from a few months to a year
Sometimes, tropical fish become trapped and wash
up along NS
Cold core rings are “bubbles” of colder water
surrounded by the warmer waters of the Gulf Stream
What is upwelling?
• Winds blowing across the ocean away
from land tend to push warmer, surface
water away from the land. Colder water
from the ocean bottom rises up to replace
this water.
• The colder upwelling water carries many
nutrients for plant growth, which supports
a huge ecosystem.
• Demo
• Video
Major Areas of Upwelling:
TIDES
What causes tides?
• Tides Explained
• Tides
The tides are caused by the difference in the
force of gravity between the end of the Earth
closest to the Moon, and the opposite end,
which is furthest away. While the Moon is pulling
at the waters of the seas closest to it, causing a
high tide, at the opposite end of the Earth, the
pull is the least. This causes the waters to bulge
away from the Moon, and therefore another
high tide is formed on the side furthest away
from the Moon. Somewhere in between these
two points of high tides are two areas of low
tides. This is what causes two high tides and
two low tides daily.
Animation on Tides
Spring & Neap Tides
When the Sun & Moon are aligned, higher
than normal high tides occur. This is called
spring tide.
When the Sun & Moon are at right angles,
lower than normal high tides occur. This
is called neap tide.
Label high & low tides on this
diagram and explain
More on Tides:
• A tide is like a huge wave that is bulging out
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from the Earth. This wave (or high tide) enters
bays, harbours, etc. Certain bays are shaped in
such a way that extra high tides are produced.
This is the case with the Bay of Fundy.
At the head of the Bay of Fundy, the difference
between high & low tides is about 14 metres (42
feet). Here, the tidal current has a speed of
about 15 km/h
Time lapse video
Bay of Fundy
• In Nova Scotia, we have two high tides
and two low tides every day. This is
called semi-diurnal. Other areas of the
world have one high and one low tide
every day. This is called diurnal.
Tide Table for Sydney, NS
What is a tidal boar?
• A tidal boar is when the incoming high
tide is slowed by the water coming out of
a river. As a result, a large wave (or
“boar”) is produced.
• This occurs in the Salmon River near Truro
• The tidal boar near the mouth of the
Amazon River is 5m high and moves at 22
km/h (fast enough for surfing)
What is a storm surge?
• A storm surge can occur during severe
storms and hurricanes. Three factors
have to be present:
1. High on-shore winds
2. Extreme low pressure
3. High tides
• These conditions cause massive coastal
flooding and destruction.
Basic Physics of Waves:
Ocean Waves
There are two general types of ocean waves:
1. Progressive waves
-These waves continue moving forward
-Ex. A rock tossed into the ocean
2. Standing waves
-This happens when water sloshes back
and forth as in a bathtub
-Ex. Happens in ponds; Great Lakes;
Northwest Arm of Halifax Harbour
Demo of a standing wave
Types of Progressive Waves:
1.Capillary waves
2.Gravity waves
3.Tides
4.Tsunami
Capillary Waves:
• These are the smallest waves with a very
small wavelength of less than 1.73cm.
Wind blowing over calm waters causes
these tiny waves (like ripples). As soon as
the wind stops, the surface tension (or
“stickiness”) of the water causes the water
to become calm again.
• Video
Photo of Capillary Waves
Gravity Waves
• These are the most common types of
waves. The wavelength of gravity waves
is greater than 1.73 cm. Gravity is the
only force that will stop these waves and
restore the sea surface to a calm state.
Ocean/Gravity Waves
Gravity vs. Capillary Waves:Video
Surfing Waves in Hawaii:Video
Rough Seas
Tsunamis
• This means big wave in harbour in
Japanese
• A tsunami is a huge wave with a very
large wavelength (hundreds of kilometres)
• Tsunamis are caused by earthquakes,
rockslides, volcanoes, meteor impacts and
even an atomic bomb blast
National Geographic Video
Scuba Diving in Tsunami
Tides
• Tides are the biggest waves in the oceans
• Tides have a wavelength (from one crest
to the next) of ½ of the circumference of
the Earth.
Rogue Waves
•These are higher than normal waves, that come out of
nowhere.
•Rogue waves are very dangerous for boaters, and
beach goers.
Rogue Waves: News Video 1
Rogue Waves: News Video 2
How do ocean waves form?
• Most surface waves are caused by the wind.
• As the wind blows, it pushes the water.
This energy continues to pass along,
forming a wave of water.
What affects the height of waves?
1. The area of open water the wind can blow
over (this is called fetch)
2. The strength of the wind
• The stronger the wind and the longer the fetch (or
distance), the bigger the waves
Beaches & Erosion
• Why do waves crash along the shore?
The actual cresting wave begins to form when
the depth of the water is 1/7 of the wavelength.
So, if the wavelength is 7m, the wave will crash
when the water is 1m deep
• What is beach erosion?
Waves usually hit beaches at an angle,
causing the waves to bounce back out into
the water. In this way, a current is
formed. This is called a longshore
current. It is this current that causes
beach erosion.
Animation
• Beaches are dynamic and always changing
due to erosion (taking away) and
deposition (building up).
• More erosion occurs in the winter because
there are storms with more wave energy.
• So, beach erosion is a natural
phenomenon that occurs along coastlines.
• However, people feel that with Global
Warming and rising sea levels, beach
erosion may be more severe in the years
to come.
How does human activity affect
beach erosion?
More erosion occurs due to the following:
1. Rising water levels (due to melting icecaps
because of global warming)
2. Removing sand & rocks from beaches
3. Busy ports change the currents that naturally
transport sand
4. Beachside construction may destroy sand
dunes that protect beaches
5. Beach goers may trample vegetation that helps
to stabilize the shoreline.
What have people done to slow
erosion?
1. Structures called groins are built into the
water to slow erosion. The problem is
that erosion still occurs on one side and
not the other.
2. Build a seawall
However, seawalls
become undercut over
time
3. Beach nourishment
This involves adding sand, rocks, etc. to
a beach that is eroding. This is the best
solution (or most natural). But, this only
slows erosion. Simply put, beach
erosion cannot be stopped.
Oceans 11 Module 2:
The Marine Biome
What is a biome?
A biome is a distinct natural community
consisting of certain types of plants,
animals and other organisms. A biome
has a certain type of climate and
geography.
There are many types of biomes (ex. Desert
biome, arctic biome, rainforest biome).
The marine biome is the largest on Earth.
• What is the marine biome?
This is the living (or “bio”) part of the ocean.
• What is needed to support life in the ocean?
1. Sunlight
2. Oxygen
3. Food or nutrients
4. Water
These are called limiting factors because they
limit or control life. In other words,
organisms are controlled by the amount of
oxygen, sunlight, food and water.
Comparing Marine Biome with
the Terrestrial Biome
Terrestrial Biome
Marine Biome
1. Air Pressure: Stays the same
1. Water Pressure: Increases with
depth
2. Temperature: Drastic
temperature extremes
2. Temperature: Slow temperature
changes; many areas have a constant
temperature
3. Oxygen: Usually plenty of oxygen 3. Oxygen: Some areas have low
oxygen levels
4. Weather: Changing weather
conditions all of the time
4. Weather: Most of the ocean is not
affected by weather (just the first few
metres)
5. Sunlight: Lots of sunlight
5. Sunlight: Amount of sunlight
decreases with depth
Light
• The amount of light in the ocean is an important factor
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in determining the level of photosynthesis (more light
means more photosynthesis).
In general, the maximum depth of photosynthesis is
125m (actually, it is 125m in clear tropical waters in
places like the Caribbean, but only 10m in the waters off
NS).
The amount of light getting through depends on
sediments, sewage and other organisms in the water.
The uppermost layer of the ocean where light is present
is productive (produces or makes food) while the rest
of the ocean is consumptive (consumes or eats).
Pressure
• Every 10m of the depth = the pressure of air on
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land (or, 1 atmosphere).
In the Marianna Trench, the pressure is 1100
atmospheres.
Scientists once thought that pressure limited
biological activity, but deep water organisms
have adapted over millions of years
Deep water organisms cannot survive in
shallower water/lower pressure conditions, while
shallow water organisms are unable to
withstand high pressures.
Temperature
• Differences in temperature causes species variation (changes) from
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north to south (tropical species at the Equator; polar species at the
North and South Poles)
Polar species (at the poles; within the Arctic Ocean)
Boreal species (near the poles; NS to Labrador)
Temperate species (from North Carolina to NS/Nfld.)
Tropical species (at the Equator)
Temperature also causes a different distribution with respect to
depth (e.g. shrimp migrate vertically according to the temperature
and time of year)
Obviously, species become adapted to a certain temperature range,
and are unable to survive if the water temperature is outside of this
range (too hot or too cold)
Ocean water can cool below 0°C and still remain a liquid. As a
result fish often have special “antifreeze compounds” in their blood
In general, northern organisms are usually more robust, and often a
lot more feeding takes place in northern waters (e.g. whales
migrate north in the summer months because there is more food
here in the summer than there would be in the tropical ocean)
Light Zones in the Ocean
1. Sunlight Zone (or euphotic zone)
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-This is the top layer of the ocean
-Because photosynthesis occurs here, 90% of marine
life is here
-Goes down as far as 600 feet
Twilight Zone (disphotic zone)
-Very little light present; high pressure
-No photosynthesis; all animals
-Very strange creatures that glow (called
bioluminescence)
Midnight Zone (aphotic zone)
-90% of the ocean is in this zone
-Extreme pressure and freezing temperatures
-Very little life except for creatures that live around
cracks in the ocean floor
Videos
• Zones of the Ocean
• Twilight Zone (not the movie!!)
• Midnight Zone (verrrryyy darrrrk!)
Hydrothermal Vents
(or “black smokers”)
Video
What is a hydrothermal vent?
• The vents are cracks in the ocean floor
that heat the surrounding water and
release sulphur chemicals
• Bacteria feed on these chemicals (called
chemosynthesis)
• Strange animals live around the vents
• All life here is based NOT on sunlight, but
on the chemosynthesis of the chemical
eating bacteria.
More on Light Zones
Depth
Characteristics
0 – 200 metres
-Layer of plant production
-Roughly the depth of the continental shelf
200 - 1000 metres
-Very little light
-Big decrease in temperature
-The amount of available food decreases
4000 metres
-No light present
-Very little food of any type
-Very stable environment (constant temperature,
salinity & oxygen)
-Most stable environment on Earth
4000 – 11,000 metres
-Food is non-existent
-Pressure is extremely high
-At this depth, the only life that occurs is around
vents in the crust called hydrothermal vents
Open vs. Coastal Ocean
Characteristics of Open Ocean
Characteristics of Coastal Ocean
Deep water eliminates bottom dwelling
seaweed communities
Shallow water allows bottom-dwelling
seaweed communities to thrive
No cross currents or upwelling to help
stir up nutrients from the bottom
Many currents, tides and upwelling
areas stir up nutrients for plant growth
Far from land run-off which provides
nutrients
Close to land run-off which helps to
promote plant growth
Cooler temperatures that limit the
number of organisms
Warmer coastal temperatures promote
spawning & migration
Marine Food Webs
Non-living chemicals
Heat
Decomposers
Heat
Plants/algae
Heat
Heat
Consumers
Parts of a Food Web
• Decomposers - These are organisms that break
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down dead organisms
-In the ocean, most decomposers are bacteria,
but worms and fungus are also marine
decomposers
Non-living chemicals – Usually, these are the
chemicals needed for plant growth (nitrogen,
phosphorous, silicon)
Plants, algae & seaweed – Mostly single-celled
algae called phytoplankton. Some are seaweed
such as kelp and rockweed. A few are actual
plants such as eelgrass. These are the
producers.
• Consumers – Most marine animals are
consumers, such as fish, shellfish, seals,
whales, sharks etc.
Loss of Energy at Each Level in
a Food Chain
• There is a 90% loss of energy at each
feeding level. This energy is lost in the
form of heat. This means that only 10% of
the energy is actually transferred from one
feeding level to the next.
Marine Food Pyramid of Energy
Food Web Activity (25 pts)
• Use Google to create a food web
• Find 8-10 marine organisms found around
NS and create a simple food web.
• You will need to include an algae
(seaweed or phytoplankton), small
animals (such as copepods or krill; clams,
snails, mussels), smaller fish, bigger fish,
and then maybe larger predators (seals,
whales, sharks)
Photosynthesis & Primary
Productivity
• Primary productivity is the production of
sugar (or “food”) by plants, algae &
seaweed. It is called “primary” because
the entire marine food web depends on
this process.
• Primary productivity occurs because of a
reaction called photosynthesis
• Photosynthesis occurs in all plants,
seaweed and algae.
Photosynthesis Reaction
• Carbon dioxide and water react with
sunlight (a type of energy) to form sugar
and oxygen.
• CO2 + H2O
CH2O + O2
sunlight
chlorophyll
• An important chemical called chlorophyll
that is present in all plants & algae makes
this reaction possible
• So, in many ways, chlorophyll is the most
important chemical in the ocean.
Oceans 11 Quiz
1. Name three (3) light zones.
2. Which part of the ocean is most
productive: open or coastal ocean?
3. What is primary productivity?
4. Name two (2) producers in the ocean.
5. What percentage of energy is lost from
one level of a food web to the next level?
Oceanic Organisms
All organisms in the ocean can be classified
according to where they live:
1. Plankton: comes from the Greek word
“planktos” meaning “to drift”. Plankton drift
about in the ocean. Plankton are unable to
swim against the currents.
Ex. jellyfish
2. Nekton: these are organisms (mainly animals)
that are able to move freely instead of just
drifting. Ex. Fish
3. Benthic organisms: these are organisms that
live on the ocean bottom or in the ocean
sediments. Ex. worms
The Ocean’s Green Machines
• Video
Types of Plankton
There are three main types of plankton:
1. Phytoplankton: single-celled algae
(seaweed) that undergo photosynthesis
2. Zooplankton: usually tiny animals that
float in the ocean. Zooplankton feed
mainly on phytoplankton
3. Meroplankton: floating larvae
(juveniles) from certain types of
organisms.
Diatoms and Dinoflagellates
(Phytoplankton)
Along with certain types of bacteria, diatoms
and dinoflagellates are the most important
producers in the marine ecosystem. Diatoms
and dinoflagellates are one-celled algae or
“plants” which we call phytoplankton. All
phytoplankton are the basis for nearly every
marine food chain. In fact, phytoplankton
produce nearly 90% of all food in the ocean,
and about 2/3 of all food on Earth.
Phytoplankton filter carbon dioxide (a waste
gas released by animals) while producing
important oxygen.
Diatoms:
• Most abundant type of phytoplankton
• Thousands of different species with a
huge variety of shapes and colours
• Live in “glass houses” (make delicate
shells in two halves that fit together)
• Dead diatoms sink to the bottom forming
layers of sediments that are hundreds of
metres thick
Images of Diatoms:
Dinoflagellates
• Some are plant-like, while others are
actually parasites and carnivores
• Some actually live within the issues of sea
anemones and corals
• Some are responsible for harmful algal
blooms (or “red tides”)
Zooplankton (animal plankton)
• These are like insects in the sea
• Zooplankton are probably as plentiful as
land insects and just as important
• Zooplankton feed directly on
phytoplankton, and form the second level
in most marine food webs.
• Most zooplankton are food for larger
animals such as fish and whales.
• Two common types of zooplankton are
copepods and krill
Copepods
Krill
What is an algal bloom or
phytoplankton bloom?
• An algal bloom happens when phytoplankton grow
•
•
very quickly and form dense patches near the
surface of the water.
These blooms normally happen in the early spring
and late summer, but sometimes blooms can be
harmful because some types of dinoflagellates
produce powerful poisons that get into the food
web. This kind of a bloom is called a “red tide”
Red tides produce poisons called paralytic shellfish
poisons (or PSP’s)
Algal Bloom Videos
• http://youtu.be/Jaq6B3fMe3Y
• http://youtu.be/OUeAMzoKNWg
Questions
1. What are harmful algal blooms (HAB’s)?
2. What are some of the causes of HAB’s?
3. What are paralytic shellfish poisons (or
PSP’s)?
4. What are some of the effects of PSP’s?
5. What are some of the effects of PSP’s on
humans?
Atlantic Canada Fisheries
1. What are the most productive (or
biggest) fisheries in Atlantic Canada?
2. What is the richest fishery in terms of
money?
3. What species are caught by fishers from
Eskasoni?
4. What happened to the cod fishery in the
early 1990’s? What is the current health
of the cod fishery?