Estuaries – Where salt meets fresh

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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?

c) d) a) b) 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: c) d) a) b) 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?

c) d) e) a) b)

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 c) d) a) b) 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?

c) d) e) a) b)

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 c) d) a) b) 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?

c) d) a) b) e)

Horseshoe crab

Indian Western Manatee

Western Sandpiper

Florida Manatee

Whitefish

Multiple Choice Question #4

The correct answer is c) d) a) b) e)

Horseshoe crab

Indian Western Manatee

Western Sandpiper

Florida Manatee

Whitefish

Multiple Choice Question #5

How have humans impacted estuaries?

c) d) a) b) 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 c) d) a) b) 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

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