Coastal wetlands like estuaries, salt marshes, and mangrove swamps provide important habitat for many marine plants and animals. However, they are threatened by human pollution from sewage, industrial waste, and agricultural runoff. Estuaries in particular cannot cope with excessive human pollution levels. [/SUMMARY]

1. Coastal Wetlands
• Land areas covered by salt
water at least part of the
year are called coastal
wetlands
• Provide habitat and nesting
for fish and wildlife
• Absorb excess rain to help
prevent flooding
• Filter out pollutants and
sediments

2. Plants and Animals of
Estuaries
Estuaries support many
marine ecosystems
Rivers supply nutrients that
have washed from the land
Sunlight and nutrients
support large populations of
plants and plankton
Larger marine animals feed
from estuaries

3. Threats to Estuaries
In populated areas, they
were used as landfills
Pollutants include sewage,
industrial waste, and
agricultural runoff
Estuaries cannot cope with
the excessive amounts of
human pollution

4. Salt Marshes
In estuaries, where rivers
deposit mineral rich mud,
salt marshes form
Salt marshes support
communities of clams, fish,
and aquatic birds
Act as a nursery for shrimp,
crabs, fish which are then
consumed by other ocean
animals or people

5. Mangrove Swamps
Mangroves are several
species of small trees
adapted for growing in
shallow salt water
Mangroves have wide,
above-ground root systems
for support
Dense growth of mangroves
in swampy areas are
mangrove swamps
They help protect the
coastline from erosion

6. Rocky and Sandy Shores
Rocky shores have more
plant and animal diversity
than sandy shores
Rocks anchor seaweed, sea
anemone, mussels, and
sponges
Sandy shores has abundant
life in the water and sandy
sediments
Barrier islands run parallel to
sandy shores and protect the
mainland from storms

7. Coral Reefs
Coral reefs are limestone
ridges built by tiny coral
animals called coral polyps
that secrete skeletons of
limestone that slowly
accumulate into reefs
Thousands of species of
marine plants and animals
live in the cracks of reefs
making them among the most
diverse ecosystems on Earth
Are only found in shallow,
warm salt water

8. Coral Reefs in Danger
Coral reefs are fragile
ecosystems
If the water gets too hot, too
cold, too polluted for too
long, the algae that live there
will move or die--when this
happens, the coral turns
white and is known as coral
bleaching
Bleaching is occurring more
frequently now because of
human activity

9. Oceans
Sunlight penetrates only
about 100 m (330 ft)
As a result, much of the
ocean's life is concentrated
here
Seaweed and algae grow
anchored to rocks and
phytoplankton drift on the
surface

10. Plants and Animals of Oceans
Phytoplankton grows only
where there is enough
sunlight and nutrients
This makes the open ocean
one of the least productive
ecosystems
Phytoplankton use oils and
air bubbles to keep from
sinking to the bottom
The smallest herbivores (jelly
fish shrimp, fish larvae) live
near the phytoplankton they
eat

11. Deeper in the Ocean
The depths of the ocean are
perpetually dark
Most of the food is dead
organisms
Decomposers and filter feeders
will be found here

12. Threats to the Ocean
Oceans are steadily
becoming more polluted
Runoff from fertilized fields
may cause algal blooms
Waste from cities and
industries, fertilizers, and
sewage are the main sources
of pollution
Overfishing is destroying
some fish populations

13. Arctic and Antarctic Ecosystems
Ecosystems are marine
The Arctic Ocean is nutrient
rich because of surrounding
land masses
The Antarctic is the only
continent never colonized by
humans
Plankton is the basis for both
of these food webs

14. Copy Now, Answer Later
Explain why estuaries are very productive
ecosystems. Why are estuaries vulnerable to the
effects of pollution?
Compare salt marshes with mangrove swamps.
Describe two factors that can damage coral reefs.
List two ways in which animals of the oceans are
threatened.
Suppose the sea suddenly rose 100 m. What would
happen to the world's coral reefs? Explain.