chesapeake bay. chesapeake as an estuary an estuary is: a semi-enclosed body of water that has a...
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CHESAPEAKE BAY
Chesapeake as an EstuaryChesapeake as an EstuaryAn An estuaryestuary is: is:
• a semi-enclosed body of a semi-enclosed body of water that has a free water that has a free connection with the seaconnection with the sea
• where seawater is mixed with where seawater is mixed with freshwater runoff from the freshwater runoff from the land.land.
.
-4- Estuary Types-4- Estuary Types• Drowned River ValleyDrowned River Valley• Bar-Built EstuaryBar-Built Estuary• Tectonic EstuaryTectonic Estuary• FjordsFjords
Estuary Estuary TypesTypes
Drowned River ValleyDrowned River ValleyThis is the most common type of This is the most common type of
estuary. estuary. • Forms during an ice age from Forms during an ice age from
glacial melt. glacial melt. • The Chesapeake Bay is a drowned The Chesapeake Bay is a drowned
river valley river valley (Susquehanna(Susquehanna))• 12,000 – 18,000 years ago12,000 – 18,000 years ago
Bar-Built Estuaries• Found whereFound wheresand barssand barsand barrierand barrier islands form.islands form.(Outer Banks of NC)(Outer Banks of NC)
Bar-Built Estuaries• The shallow The shallow water behind water behind these barrier these barrier islands forms islands forms low salinity low salinity estuariesestuaries.
Tectonic Estuaries• These These estuaries estuaries form where form where the land sank the land sank (subsided).(subsided).
Fjords!• Fjords were Fjords were
created created when when retreating retreating glaciers cut glaciers cut deep in the deep in the earth.earth.
Fjords!• Where in the Where in the United United States might States might we find we find fjords?fjords?
A A watershedwatershed is the is the drainage area for a drainage area for a
region.region.
Virginia’sVirginia’s WatershedsWatershedsThere are 3 Different Watersheds There are 3 Different Watersheds in VA.in VA.–The Chesapeake BayThe Chesapeake Bay–The Gulf of MexicoThe Gulf of Mexico–The North Carolina The North Carolina SoundsSounds
Gulf of Gulf of MexicoMexico
Chesapeake Chesapeake BayBay
North Carolina North Carolina SoundsSounds
Facts About The Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States.
•Can you name the Can you name the 6 6 statesstates that make up that make up the watershed of the watershed of the Chesapeake the Chesapeake Bay?Bay?
• VirginiaVirginia• MarylandMaryland• West VirginiaWest Virginia• DelawareDelaware• New YorkNew York• PennsylvaniaPennsylvania
Chesapeake Chesapeake Bay WatershedBay Watershed
Maryland
DelawareDelaware
New York
District of Columbia
Virginia
West Virginia
Pennsylvania
The water The water from over from over 5050 rivers rivers
empties into empties into the Bay. the Bay. Can you Can you
name the name the 55 major riversmajor rivers that flow into that flow into
the bay?the bay?
• From South to NorthFrom South to North• JamesJames• YorkYork• RappahannockRappahannock• PotomacPotomac• SusquehannaSusquehanna
(JYRPS!)(JYRPS!)
Susquehanna Susquehanna RiverRiver
Potomac RiverPotomac River
Rappahannock RiverRappahannock River
York RiverYork River
James RiverJames River
The Susquehanna RiverThe Susquehanna River provides about provides about 50%50% of the of the fresh water coming into the fresh water coming into the Bay.Bay.
• The river empties an average The river empties an average of of 19 million gallons of water 19 million gallons of water per minute.per minute.
• The Bay holds 18 trillion gal.The Bay holds 18 trillion gal.
The bay is shallow. Can The bay is shallow. Can you guess its average you guess its average
depth?depth?• 106 ft.106 ft.• 21 ft.21 ft.• 9ft.9ft.
THE ANSWER!THE ANSWER!• 21 feet is the correct answer.21 feet is the correct answer.
• The deepest spot in the bay The deepest spot in the bay is 174 feet near Annapolis is 174 feet near Annapolis Md.Md.
Colonization of Estuaries
• For those For those organisms that organisms that can survive the can survive the extremes of the extremes of the estuary, (temp., estuary, (temp., salinity, oxygen) salinity, oxygen) there is a great there is a great deal of food.deal of food.
Bay OrganismsBay Organisms• The Bay is home to over The Bay is home to over
3600 living organisms!3600 living organisms!2700 – plants2700 – plants348 – finfish348 – finfish
173 - shellfish173 - shellfish
Marsh DwellersMarsh Dwellers• Marsh dwellers Marsh dwellers
are located in are located in and around and around tidal mudflats. tidal mudflats. They include They include small fish, small fish, birds, and birds, and marsh marsh grasses.grasses.
SAV CommunitiesSAV Communities• Submerged Aquatic Submerged Aquatic
Vegetation Vegetation CommunitiesCommunities are are important for many important for many reasons. They reasons. They provide shelter for provide shelter for organisms organisms including fish including fish ducks, crabs, and ducks, crabs, and eelgrass.eelgrass.
Plankton CommunityPlankton Community• The plankton The plankton community community includes the includes the drifters drifters of of the Bay. the Bay.
Plankton CommunityPlankton CommunityIncludes Includes phytoplankton, phytoplankton, bacteria, and bacteria, and zooplankton.zooplankton.
Benthic CommunitiesBenthic Communities• Benthic refers Benthic refers
to the bottom of to the bottom of the Bay. Benthic the Bay. Benthic organisms organisms include oysters, include oysters, clams, clams, barnacles, and barnacles, and mud crabs.mud crabs.
Nekton CommunitiesNekton Communities• Nekton refers Nekton refers
to the to the swimmers of swimmers of the Bay,the Bay,
many of which many of which use the Bay use the Bay as a nurseryas a nursery
The Bay area is home to over 15,000,00015,000,000 people!
• About 50,00050,000 commercial vessels enter the Bay each year.
• All of these people and activities put a strain on the Bay ecology.
Bay Problems Nutrient PollutionNutrient Pollution
• Fertilizers, manure & sewage Fertilizers, manure & sewage add nitrogen and add nitrogen and phosphorus to the Bay.phosphorus to the Bay.
• These cause increased algae These cause increased algae growth (algal bloom)growth (algal bloom)
• Algae blocks sunlight Algae blocks sunlight from bottom dwellers.from bottom dwellers.
• As the algae dies, it uses As the algae dies, it uses up oxygen.up oxygen.
• Not enough oxygen left Not enough oxygen left for animals.for animals.
Sources of NutrientsSources of Nutrients
FarmsFarms
Urban Urban AreasAreas
Wastewater Wastewater treatment treatment plantsplants
Bay ProblemsLoss of Submerged Aquatic Loss of Submerged Aquatic
Vegetation (SAV)Vegetation (SAV)• Plants that are found on the bottom Plants that are found on the bottom
of the bay provide food and shelter of the bay provide food and shelter for organismsfor organisms
• These plants are dying because of These plants are dying because of pollution and sedimentation.pollution and sedimentation.
Bay ProblemsToxinsToxins
• Harmful chemicals can be Harmful chemicals can be added to the bay from added to the bay from industries, roads, farms and industries, roads, farms and homes.homes.
Examples: pesticides, Examples: pesticides, herbicides, chemicals, oil herbicides, chemicals, oil productsproducts
Pollution Sources• Point Sources-Point Sources- pollutants pollutants
that come from a specific that come from a specific source that can be identified source that can be identified (factories,(factories,
sewagesewageoutflows)outflows)
• Non-point Sources-Non-point Sources- pollutants pollutants that come from a large region that come from a large region and can’t be identified from a and can’t be identified from a specific site (ex- farm runoff or specific site (ex- farm runoff or sedimentssediments
LawnsLawns
Parking lotsParking lots
Pesticides)Pesticides)
Bay ProblemsBay Problems Exotic SpeciesExotic Species
• Some plants and animals are Some plants and animals are accidentally or intentionally accidentally or intentionally introduced into the Bay Area introduced into the Bay Area (ex. Zebra mussel, snakehead, (ex. Zebra mussel, snakehead, water milfoil, Rapa whelk)water milfoil, Rapa whelk)
• Have no natural predators so Have no natural predators so they are hurting the ecosystem.they are hurting the ecosystem.
