CHESAPEAKE BAY

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CHESAPEAKE BAY
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Chesapeake as an Estuary

• An estuary is a semi-enclosed body of water that
  has a free connection with the sea

• .

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Chesapeake as an Estuary

• Estuaries have more food for organisms, but the
  organisms usually have to deal with large
  temperature and salinity changes, high silt
  content and pollution.

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Why do you think high silt would be a problem for
marine organisms?

• Hint How does this organism get its food?

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Many marine organisms are filter feeders so silt
can be a major problem.
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Many of these filter feeders are important as
food to humans.
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Colonization of Estuaries
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• Estuaries are regions of transition and sharp
  gradients.
• Estuaries support fauna recruited mostly from the
  sea

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• The number of species in an estuary is greatly
  reduced, but the number of individuals is large.
• What does that mean? Can you explain that last
  statement?

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The Answer

• For those organisms that can survive the problems
  of the estuary, there is a great deal of food.

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The Answer

• These organisms tend to be in large numbers.

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Estuary Types

• The Chesapeake Bay is a drowned river valley.
  This is the most common type of estuary. It was
  formed during the last ice age some 12,000
  18,000 years ago.

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Estuary Types

• The Chesapeake Bay is a drowned river valley.
  This is the most common type of estuary. It was
  formed during the last ice age some 12,000
  18,000 years ago.
• There are other types of estuaries. Can you name
  any of them?

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Bar-Built Estuaries

• These are found where sand bars and barrier
  islands form.

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Bar-Built Estuaries

• The shallow water behind these barrier islands
  forms low salinity estuaries.

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Tectonic Estuaries

• These estuaries form where land sank or subsided.

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Tectonic Estuaries

• A good example of this type of estuary is San
  Francisco Bay.

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Do you know the name of the last type of estuary?

• Think Ice!

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Fjords!

• Fjords were created when retreating glaciers cut
  deep in the earth.

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Fjords!

• Where in the United States might we find fjords?

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Facts About The Chesapeake Bay
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The Chesapeake Bay is the largest estuary in the
United States.
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The bay is shallow. Can you guess its average
depth?

• 106 ft.
• 56 ft
• 32 ft.
• 21 ft.
• 14ft.
• 9ft.

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THE ANSWER!

• 21 feet is the correct answer. The deepest spot
  in the bay is 174 feet near Annapolis Md.

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A watershed is the drainage area for the bay.

• Can you name the 6 states that make up the
  watershed of the Chesapeake Bay?

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• Virginia
• Maryland
• West Virginia
• Delaware
• New York
• Pennsylvania

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Can you name the 5 major rivers that flow into
the bay?

• From South to North
• James
• York
• Rappahannock
• Potomac
• Susquehanna

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Which of those 5 rivers contributes the most
fresh water to the bay?

• The Susquehanna River provides about 50 of the
  fresh water coming into the Bay.
• The river empties an average of 19 million
  gallons of water per minute.

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Can you name a mammal that is named after the Bay?

• Think you know?
• The Chesapeake Bay Retriever

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The Bay area is home to over 15,000,000 people!

• About 50,000 commercial vessels enter the Bay
  each year.

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The Bay area is home to over 15,000,000 people!

• All these people and activities put a strain on
  the Bay ecology.

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Bay Organisms

• The Bay is home to over 3600 living organisms!

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Marsh Dwellers

• Marsh dwellers are located in and around marshes.
  They include small fish, birds, and marsh grasses.

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SAV Communities

• Submerged Aquatic Vegetation Communities are
  important for many reasons. They include ducks,
  crabs, and eelgrass.

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Plankton Community

• The plankton community includes the drifters of
  the Bay.

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Plankton Community

• It includes phytoplankton, bacteria, and
  zooplankton.

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Benthic Communities

• Benthic refers to the bottom of the Bay. Benthic
  organisms include oysters, clams, barnacles, and
  mud crabs.

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Nekton Communities

• Nekton refers to the swimmers of the Bay.

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Nekton Communities

• Croaker, Spot, and menhaden use shallow water in
  the Bay as a nursery