Transcript 15.2 weebly

15.2 – The Diversity of
Ocean Life
S
Do Now
SHow are marine
organisms classified?
Do Now
SHow are marine
organisms classified?
S According to where they live and
how they move.
Key Words
SMarine
SPropulsion
Vocab Words
SBenthos
SNekton
SPlankton
Classification of
Marine Organisms
S Marine organisms can be classified
according to where they live and
how they move.
S Plankton
S Nekton
S Benthos
Plankton
S Plankton include all organisms—algae,
animals, and bacteria—that drift with
ocean currents. They are also known
as drifters.
S Planktos = “wandering”
Plankton
S Phytoplankton - are algae plankton, which
are the most important community of
primary producers in the ocean. They
undergo photosynthesis. They are
microscopic. Ex: Diatom
S Zooplankton - are animal plankton.
Include the larval stages of marine
organisms. Such as fish, crab, shrimp, etc.
Nekton
SInclude all animals capable of
moving independently of the
ocean currents, by swimming
or other means of propulsion.
SIncludes most adult whale,
squid, shark and fish.
Benthos
SDescribes all organisms
living on or in the ocean
bottom.
SMost benthos organisms can
be found in shallow intertidal
Marine Life Zones
SThree factors are used to divide
the ocean into distinct marine life
zones: the availability of sunlight,
the distance from shore, and the
water depth.
Availability of
Sunlight
S The photic zone is the upper part of
the ocean into which sunlight
penetrates.
S The aphotic zone is the lower part of
the ocean into which no sunlight
exists.
Distance from Shore
S The intertidal zone is the strip of land where the
land and ocean meet and overlap, or the zone
between high and low tides.
S The neritic zone is the marine-life zone that
extends from the low-tide line out to the shelf
break.
S The oceanic zone is the marine-life zone beyond
the continental shelf.
Water Depth
S The pelagic zone is open zone of any depth.
Animals in this zone swim or float freely.
S The benthic zone is the marine-life zone that
includes any sea-bottom surface regardless of its
distance from shore.
S The abyssal zone is a subdivision of the benthic
zone characterized by extremely high pressures,
low temperatures, low oxygen, few nutrients, and
no sunlight.
Hydrothermal Vents
S Here seawater seeps into the ocean
floor through cracks in the crust.
S At some vents, water temperatures of
o
100 C or higher support communities
of organisms found nowhere else in
the world.
Group Challenge
Question
S It has been observed that some species
of zooplankton migrate vertically in
ocean water. They spend the daylight
hours at deeper depths of about 200
meters and at night move to the
surface. Formulate a hypothesis that
might explain this behavior.