Download Oceanic Zone

WATER!
 75% of the Earth’s surface is covered with water
 70% of the Earth’s surface is the ocean
These aquatic ecosystems can be divided into many
different types based on the salt level, locations and
depth.
OCEAN ZONES
The zones of the ocean are determined based on:
 Availability of light
 Amount of salt (salinity)
 Depth of the water
 Aphotic zone – area where sunlight canNOT
penetrate. No photosynthesis takes place here
 Photic zone – area where sunlight reaches, lots of
photosynthesis occurs in this region, it is a few
hundred meters deep
The ocean can also be divided based on how
close to shore and depth of water
 Intertidal zone –
 Area of shoreline that is twice daily covered by water
during high tide and is exposed to air during low tide
 Also exposed to crashing waves
 Organisms that live here must be adapted to the
changing conditions and have a way to deal with the
force of the waves
 Exs: crabs, clams, mussels, starfish, sea anemones
 Neritic Zone –
 Area from end of intertidal to the edge of the
continental shelf.
 Relatively shallow (180 meters deep)
 Most productive zone of the ocean – coral reefs are
found here along with hundred of species
 Lots of nutrients and plankton are available here
 Exs: fish, turtles, coral, crustaceans, mollusks
 Oceanic Zone
 Deep water of open ocean
 Fewer species
 Not as many nutrients
 Lots of plankton
 ½ of the world’s photosynthesis takes place here
 Can be further divided

PELAGIC – open ocean

BENTHIC – ocean bottom, dark and cold
Estuary
 Areas where freshwater rivers and streams flow into
the ocean Ex: Chesapeake Bay
 Examples are mud flats, bogs, salt marsh, swamp
forest
 Inhabitants are these areas are adapted for frequent
change!
 Rich in species – provide areas for animals to breed,
raise young and rest during migrations
Estuary
Estuary
Estuary
FRESHWATER
 Salt concentration of 0.005%
 Includes lakes, ponds, streams, rivers
 Types of lakes:
 Eutrophic – rich in organic matter/vegetation, water is
murky, lots of algae growth, may use all available oxygen
and cause death of many organisms
 Oligotrophic – little organic matter/vegetation, water
is clear, bottom is sandy or rocky
Eutrophic Lake
Eutrophic Lake
Oligotrophic
Oligotrophic
Rivers and Streams
 Freshwater that flows
 Organisms are adapted to currents and have various
methods to hold on to rocks, shore and capture food in
the flowing water
 Slower moving streams and rivers have more life than
swiftly moving ones.
WETLANDS
 Areas where water covers the land for part of the year
 2 types
 Swamps – woody plants (trees/shrubs)
 Marshlands – nonwoody plants (cattails/grasses)
Importance of Wetlands
 Most productive freshwater ecosystem
 Home to a wide variety of animals and plants
 Provide nesting areas for birds
 Many animals use them for breeding/raising young
 Stop for migrating birds
 Filter pollutants!
 Prevent flooding!
Florida
Everglades