2. Life in the marine environment
We’ve learned a lot about the biology of different
types of marine organisms
In marine science, it is important to understand why
these creatures live where they do and how they
interact with their environment
Today we will learn about marine ecology: the study
of the relationship of marine organisms with each
other and with the environment
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3. Life in the marine environment
The ocean can be divided into zones based on depth
(vertically) and distance from land (horizontally)
Different zones of the ocean have conditions that
support different organisms
What is an ecosystem?
An ecosystem is a physically distinct area that
contains a community of interacting organisms
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4. Ocean zones and continental margins
Many ocean zones are defined based on continental margins.
To help you understand ocean zones, let’s first review
continental Margins:
Continental Margin: Submerged area of continents. Include:
– Continental Shelf (flat gradually sloping seafloor) from shoreline to ~
200m; End of Shelf is called the Shelf Break
– Continental Slope (steeply sloping seafloor) seaward of shelf break
– Continental Rise (Moderately sloping seafloor) seaward of slope
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5. Pelagic and benthic zones
One simple ocean zone
classification is between the
water and the ocean floor
The water is referred to as the
pelagic zone
– Organisms that swim through the
water column are known as
nekton
The ocean floor is referred to
as the benthic zone
– Organisms that live here are
benthic organisms or benthos
Photos: NOAA
Shark: Pelagic (nekton)
Crab: Benthic (benthos)
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6. Pelagic and benthic zone divisions
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Pelagic zone divisions
(depth from surface)
Benthic zone divisions
(seafloor zones)
Supralittoral –shore above high tide
Epipelagic (0-200m) Littoral – the intertidal zone (sometimes
submerged and sometimes above water)
Mesopelagic (200-1,000m) Sublittoral – seafloor of the continental
shelf (from low tide to the shelf break)
Bathypelagic (1,000-4,000m) Bathyl – seafloor of the continental slope
to the deep ocean bottom
Abyssopelagic (4,000-6,000m Abyssal – deep ocean bottom between
the base of the slope and 6,000 m
Hadalpelagic (6,000-10,000m) Hadal – the deepest zone, below 6,000m
7. Pelagic and benthic zone divisions
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Pelagic
zone
Littoral
200m
1,000m
4,000m
6,000m
8. Species evolve traits that help them
survive in their environment
Species in different environments may evolve different
lifestyles, behaviors and physical traits
Do you remember a few ways that intertidal organisms
are adapted to their relatively harsh environment?
Species usually are not completely isolated from one
another, but interact with other species that live in a
shared environment
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9. Populations of different species interacting with one
another in a shared environment form a community
An ecosystem is a distinct physical entity with
unique abiotic (nonliving) conditions that is home to
a community of interacting species
Can you think of some marine ecosystems you have
learned about in earlier lessons, classes or
elsewhere?
Intertidal (Splash zone)
Coral Reef Beach
What is an ecosystem?
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10. Energy is transferred through ecosystems
Solar energy
is converted to
chemical
energy by
autotrophs
Primary
consumers eat
primary
producers to
get energy
Secondary
consumers eat
primary
consumers to
get energy
Photos: NOAA
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11. Life in ecosystems is interconnected
As you’ve probably already realized, the marine
environment consists of many distinct ecosystems that
contain unique organisms
How do you think life within ecosystems is
interconnected?
Marine organisms form relationships with one another
and share space and resources
As a result, an impact on a single species in an
ecosystem can affect many other species in the same
ecosystem
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12. Important interactions
It is important to manage our
natural resources in a way that
reflects the interconnectedness of
ecosystems and their
components
Ecosystem-based management
(EBM) is a management
approach that includes these
interactions instead of
considering single species or
single issues at a time
NOAA applies EBM in its
management of marine resources
Management of ecosystems, like this bleached
coral reef, requires looking beyond just the
coral itself. Other important factors to study
might include pollution, development,
watershed management and interactions with
other species.
Photo: NOAA
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13. Student activity: Ecosystem case study on
an estuary
An estuary is a body of water that forms where
freshwater from rivers and streams flows into the ocean
and mixes with seawater to form a unique and productive
ecosystem
One of our nation’s most valued ecosystems, the
Chesapeake Bay, is an estuary
– In fact, it is one of the largest estuaries in the world
In today’s exercise, you will analyze data about the blue
crab to make inferences about the health of the
Chesapeake Bay ecosystem
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