CHESAPEAKE BAY

B B

Chesapeake as an EstuaryChesapeake as an Estuary

An estuary is a semi-enclosedbody of water that has a freeconnection with the seaAn estuary is a semi-enclosedbody of water that has a freeconnection with the sea

Chesapeake as an EstuaryChesapeake as an Estuary

Estuaries have more foodfor organisms, but theorganisms usually have todeal with large temperatureand salinity changes, highsilt content and pollution.Estuaries have more foodfor organisms, but theorganisms usually have todeal with large temperatureand salinity changes, highsilt content and pollution.

The Susquehanna River, the nation’s 16thlargest watercourse at 444 miles in length,is the largest tributary of the ChesapeakeBay, providing 90 percent of the freshwaterflow to the upper bay and half of its totalflow.

A A

T T

C C

B B

The Chesapeake Bay is the largestestuary in the United States.The Chesapeake Bay is the largestestuary in the United States.

The bay is shallow. Can you guessits average depth?The bay is shallow. Can you guessits average depth?

106 ft.106 ft.

56 ft56 ft

32 ft.32 ft.

21 ft.21 ft.

14ft.14ft.

9ft.9ft.

A A

21 feet is the correct answer.The deepest spot in the bay is174 feet near Annapolis Md.21 feet is the correct answer.The deepest spot in the bay is174 feet near Annapolis Md.

A watershed is thedrainage area for the bay.A watershed is thedrainage area for the bay.

Can you name the 6 statesthat make up the watershedof the Chesapeake Bay?Can you name the 6 statesthat make up the watershedof the Chesapeake Bay?

VirginiaVirginia

MarylandMaryland

West VirginiaWest Virginia

DelawareDelaware

New YorkNew York

PennsylvaniaPennsylvania

Can you name the 5 majorrivers that flow into the bay?Can you name the 5 majorrivers that flow into the bay?

From South toNorthFrom South toNorth

JamesJames

YorkYork

RappahannockRappahannock

PotomacPotomac

SusquehannaSusquehanna

Which of those 5 riverscontributes the most freshwater to the bay?Which of those 5 riverscontributes the most freshwater to the bay?

The Susquehanna Riverprovides about 50% of thefresh water coming into theBay.The Susquehanna Riverprovides about 50% of thefresh water coming into theBay.

The river empties an averageof 19 million gallons of waterper minute.The river empties an averageof 19 million gallons of waterper minute.

Can you name a mammal that isnamed after the Bay?Can you name a mammal that isnamed after the Bay?

Think youknow?Think youknow?

TheChesapeakeBay RetrieverTheChesapeakeBay Retriever

The Bay area is home to over15,000,000 people!The Bay area is home to over15,000,000 people!

About50,000commercialvessels enterthe Bay eachyear.About50,000commercialvessels enterthe Bay eachyear.

The Bay area is home to over15,000,000 people!The Bay area is home to over15,000,000 people!

All thesepeople andactivitiesput a strainon the Bayecology.All thesepeople andactivitiesput a strainon the Bayecology.

Bay OrganismsBay Organisms

TT

B B

i i

h h

t t

o o

l l

o o

Marsh DwellersMarsh Dwellers

Marsh dwellersare located inand aroundmarshes. Theyinclude smallfish, birds, andmarsh grasses.Marsh dwellersare located inand aroundmarshes. Theyinclude smallfish, birds, andmarsh grasses.

SAV CommunitiesSAV Communities

SubmergedAquaticVegetationCommunities areimportant formany reasons.They includeducks, crabs,and eelgrass.SubmergedAquaticVegetationCommunities areimportant formany reasons.They includeducks, crabs,and eelgrass.

Plankton CommunityPlankton Community

The planktoncommunityincludes thedrifters of theBay.The planktoncommunityincludes thedrifters of theBay.

Plankton CommunityPlankton Community

It includesphytoplankton, bacteria,andzooplankton.It includesphytoplankton, bacteria,andzooplankton.

Benthic CommunitiesBenthic Communities

Benthic refersto the bottomof the Bay.Benthicorganismsinclude oysters,clams,barnacles, andmud crabs.Benthic refersto the bottomof the Bay.Benthicorganismsinclude oysters,clams,barnacles, andmud crabs.

Nekton CommunitiesNekton Communities

Nekton refersto theswimmers ofthe Bay.Nekton refersto theswimmers ofthe Bay.

Nekton CommunitiesNekton Communities

Croaker,Spot, andmenhadenuse shallowwater in theBay as anurseryCroaker,Spot, andmenhadenuse shallowwater in theBay as anursery

Problems we have…Problems we have…

Refined Designated Uses for

Chesapeake Bay and Tidal Tributary Waters

A. Cross Section of Chesapeake Bay or Tidal Tributary

B. Oblique View of the “Chesapeake Bay” and its Tidal Tributaries

Shallow Water

Open Water

Deep Water

Deep Channel

Open Water

Habitat

Shallow Water

Habitat

Deep Water

Deep Channel

Migratory Finfish

Spawning and

Nursery Habitat

Important Habitat Requirements

Draft Bay DissolvedOxygen CriteriaDraft Bay DissolvedOxygen Criteria

Minimum Amount of Oxygen (mg/L)Needed to Survive by Species

Hard Clams: 5

Striped Bass: 5-6

Worms: 1

Migratory Spawning &Nursery Areas

Shallow and Open WaterAreas

Deep Water

Deep Channel

Crabs: 3

Spot: 2

White Perch: 5

American Shad: 5

Yellow Perch: 5

Alewife: 3.6

Bay Anchovy: 3

Draft Bay Water Clarity CriteriaDraft Bay Water Clarity Criteria

Good Water Clarity

Poor Water Clarity

Algae in the water

Sediment and otherparticles in the water

Algae on the leaves

Percent of sunlightreaching leaves:

•9% in low salinitywaters

•15% in high salinitywaters

equals

Very low percentageof sunlight reachingleaves – Bay grassesgrow poorly or die.

Why do you think high silt (solidstuff, like mud) would be aproblem for marine organisms?Why do you think high silt (solidstuff, like mud) would be aproblem for marine organisms?

Hint How doesthis organismget its food?Hint How doesthis organismget its food?

Many marine organisms arefilter feeders so silt can be amajor problem.Many marine organisms arefilter feeders so silt can be amajor problem.

Many of these filter feeders areimportant as food to humans.Many of these filter feeders areimportant as food to humans.

Colonization of EstuariesColonization of Estuaries

Estuaries are regions oftransition and sharp gradients.Estuaries are regions oftransition and sharp gradients.

Estuaries support faunarecruited mostly from the seaEstuaries support faunarecruited mostly from the sea

The number of different speciesin an estuary is greatly reduced,but the number of individuals islarge.The number of different speciesin an estuary is greatly reduced,but the number of individuals islarge.

What does that mean? Can youexplain that last statement?What does that mean? Can youexplain that last statement?

A A

For thoseorganisms thatcan survive theproblems of theestuary, there isa great deal offood.For thoseorganisms thatcan survive theproblems of theestuary, there isa great deal offood.