Neritic Zone
Ms. Bridgeland
Where is the Neritic Zone?
• Extends from the low-tide line out to the edge
of the continental shelf
• Why is the neritic zone home to so many living
things?
The Neritic Zone is home to so many
living things because:
• The shallow water over the continental shelf
receives:
– Sunlight
– Steady supply of nutrients washed from the land
into the ocean
– The light and nutrients enable large plantlike algae
to grow
– Large quantities of algae is a food source and
shelter for other organisms
Neritic Zone
• Of the three ocean zones, it
has the most constant
conditions and is easiest for
organisms to live in
Upwelling
• In the Neritic Zone, upwelling currents bring
nutrients from the bottom to the surface.
– These nutrients support plankton (the base of
food webs)
– Major fisheries in upwelling areas include:
• Monterey Canyon (off the California coast)
• Newfoundland’s Grand Banks
• Georges Ban (off the New England coast)
Coral Reefs
Coral Reef
• A diverse habitat found in the Neritic Zone
• Looks like it is made of rock, but is actually
made of living things
• Created by colonies of tiny coral animals
• Coral animals: each produce a hard structure
that surrounds its soft body
– When the coral dies, the empty structure remains
Coral Reefs can only form in shallow,
tropical ocean waters because:
– Microscopic algae live in the bodies of the coral
animals
– Provide food for the corals
– Algae need warm temperatures and sunlight
– Reefs grow above the continental shelves or
around volcanic islands where the water is
shallow
Atolls
• A ring-shaped reef surrounding a shallow lagoon
• An atoll begins as a reef that closely surrounds
the edges of a volcanic island
• As the sea-floor sinks, the island sinks with it, and
the reef continues to grow upward
• The island sinks until it is completely underwater,
and you can only see the atoll
Atoll
How Atolls Form
Types of Coral
• Elkhorn
• Brain
• Plate
• Star
Elkhorn Coral
Brain Coral
Plate Coral
Star Coral
Coral Reef Animals
• Octopus
• Spiny lobsters
• Shrimp
• Fish
Animals in the Coral Reef
What produces the fine, soft sand
around the reef?
• The Parrotfish grinds up the broken coral
inside their bodies, which produces the sand
Benefits of the Coral Reef
• Protect the coastline from violent storms
• The reefs prevent waves from severely eroding
the land
Harm to Coral Reefs
• Coral grows only a few millimeters per year, so
if a boat anchor drags across it, reefs cannot
easily recover
• Changes in water temperature and clearness
endanger the reefs
• Cloudy water harms the algae because it
reduces the amount of light reaching them
• Coral animals need to eat the algae to live