Estuaries – Where salt meets fresh
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Transcript Estuaries – Where salt meets fresh
Estuaries – Where salt
meets fresh
What are estuaries?
Estuaries are…
• Partially enclosed bodies of water where freshwater from streams
and rivers mix with saltwater from the ocean/sea
• Transition points from land to sea and from fresh to salt water.
Tidally driven, but sheltered from the full force of the ocean’s
wind and waves by reefs, barrier islands, sand, or mudflats
Transition zones between the marine-dominated systems of the
ocean and the upland river systems
Among the most biologically productive ecosystems on Earth
Picture of the Rio de la Plata
http://en.wikipedia.org/wiki/Estuary
Salt meets fresh
Picture from www.narrabay.com/empact/waterQualityInfo.asp
Freshwater is lighter than seawater and therefore flows
above it forming a bottom layer of salt water called a salt
wedge
Nutrients carried in from salt wedge transform estuaries into
very fertile areas for plant growth
Plant life in estuaries
Picture from http://www.hww.ca/hww2.asp?pid=0&id=226&cid=2
• There is more plant life in an estuary than any other habitat
1 hectare = 10000 square meters
Animals in estuaries
Estuaries contain many organisms
Some animals living in estuaries include:
– sea turtles, sea lions, mussels, clams, scallops, shrimp, snails,
amphipods, segmented worms, lugworms, and fish
– More unique animals include: horseshoe crabs, ospreys,
manatees, and mangroves
Only a few species of organisms live their entire lives in estuaries.
Other wild animals live there at some stage of their lives. Some fish
spawn in estuaries and certain species of sandpipers migrate to
estuaries and some point in the year.
http://kentsimmons.uwinnipeg.ca/16cm05/1116/33-28-HorseshoeCrabs.jpg
http://sticksoffire.com/2007/08/17/pres
erving-bullfrog-creek-and-history/
Plants in estuaries
Sea grass, lyngbyei’s Sedge, saltwort, eelgrass, cordgrass (on
Atlantic Coast), alkali grass (in the Artic), and algae
Because plants have different tolerance levels for salt, most
types of plants flourish in different areas of an estuary.
Estuaries around the world
Estuaries in the U.S. include Chesapeake Bay, San Francisco Bay,
Boston Harbor, Tampa Bay and Puget Sound
Human impact
In the past, many people believed estuaries as wasted land and
thus built dams. Dams block natural stream and river routes thus
cutting off freshwater from estuaries. When that happens, the
fresh and saltwater balance of the estuary is changed and
estuary wildlife is damaged.
Increased human growth has added more nutrients to estuaries
(mainly from sewage), which has contributed to marine animal
disease, and toxic algal blooms.
– Seafood safety has now become a concern because certain
shellfish and fish have been infected with algal toxins capable
of paralytic or diarrhetic effects on humans.
Toxic algal bloom at Lemolo
Lake
Kumgang Estuary Dam in South Korea kalaniosullivan.com/Korea/KunsanCity/Kunsan3.html
An endangered specie
The Florida Manatee is under protection from the Endangered Species
Act of 1973.
Found in Florida and southwestern Georgia in estuaries
The main cause of this is human intervention.
– Hunting has greatly reduced the population
– Pollution by humans has killed a lot of seagrass and other aquatic foods
which the Florida Manatee feeds on.
– Population growth and city development has destroyed much of the
manatee habitat
– Manatee collisions with watercrafts accounted for 78 deaths in 2000.
In October 2007, the IUCN stated that there were less than 2500
mature individuals of the Florida Manatee.
http://www.naturesresortfla.com/images/manatee1.jpg
What is so unique/important
about estuaries?
Estuaries are more than just a place for animals and plants to
live. They also help control pollution. Water from upland areas
often carries sediment and pollutants. The marshy land and
plants in estuaries filter these pollutants out of the water.
Estuaries also protect inland areas from flooding and storm
surges. When a storm hits, estuaries often absorb water from
the storm before it can reach upland areas.
South Carolina Estuaries
Ace
Basin Reserve
Winyah Bay
Port Royal Sound
Multiple Choice Question #1
What is an estuary?
a)
b)
c)
d)
e)
One of the least productive ecosystems in the
world
A habitat for only a few species able to adapt to
the environment
Transition zone between oceans and seas
Where saltwater from the ocean/sea mix with
freshwater from rivers/streams
All of the above
Multiple Choice Question #1
The correct answer is:
a)
b)
c)
d)
e)
One of the least productive ecosystems in the
world
A habitat for only a few species able to adapt to
the environment
Transition zone between oceans and seas
Where saltwater from the ocean/sea mix with
freshwater from rivers/streams
All of the above
Multiple Choice Question #2
Why are estuaries important to the
environement?
a)
b)
c)
d)
e)
They help control global warming
They help control pollution
They protect inland areas from floods and storms
A, B and C
B and C
Multiple Choice Question #2
The correct answer is
a)
b)
c)
d)
e)
They help control global warming
They help control pollution
They protect inland areas from floods and storms
A, B and C
B and C
Multiple Choice Question #3
What are some of the animals that live
in an estuary?
a)
b)
c)
d)
e)
Only plants live in estuaries
Kangaroos, Tasmanian devils, and Wombats
Fish, shellfish, horseshoe crabs, and birds
Scorpions, sea snakes, snails, and bats
Shrimp, shellfish, sharks, chickens, and marlins
Multiple Choice Question #3
The correct answer is
a)
b)
c)
d)
e)
Only plants live in estuaries
Kangaroos, Tasmanian devils, and Wombats
Fish, shellfish, horshoe crabs, and birds
Scorpions, sea snakes, snails, and bats
Shrimp, shellfish, sharks, chickens, and marlins
Multiple Choice Question #4
Which of the following species is an
example of an endangered specie in
estuaries?
a)
b)
c)
d)
e)
Horseshoe crab
Indian Western Manatee
Western Sandpiper
Florida Manatee
Whitefish
Multiple Choice Question #4
The correct answer is
a)
b)
c)
d)
e)
Horseshoe crab
Indian Western Manatee
Western Sandpiper
Florida Manatee
Whitefish
Multiple Choice Question #5
How have humans impacted estuaries?
a)
b)
c)
d)
e)
Hunting manatees
Crashing into manatees with water vehicles
Pollution of manatee waters
Destruction of manatee habitat
All of the above
Multiple Choice Question #5
The correct answer is
a)
b)
c)
d)
e)
Hunting manatees
Crashing into manatees with water vehicles
Pollution of manatee waters
Destruction of manatee habitat
All of the above
References
http://www.estuaries.gov/about.html
http://www.inforain.org/mapsatwork/oregonestuary/
http://inlet.geol.sc.edu/estecohp.html
http://www.hww.ca/hww2.asp?pid=0&id=226&cid=2
http://wps.prenhall.com/esm_thurman_introocean_9/0,
7305,348196-,00.html
http://www.epa.gov/owow/estuaries/kids/about/what.h
tm
http://www.fws.gov/northflorida/Manatee/manateegen-facts.htm