chesapeake bay
DESCRIPTION
Chesapeake Bay History Formed 12,000 years ago when the last great ice sheet melted, filling the ancient Susquehanna River. Our current coastline is approx. 70 miles more inland than the original shoreline. The FIRST incarnation of the bay area was created by a meteorite. The PRESENT day Chesapeake Bay was formed from the last ice age.TRANSCRIPT
Chesapeake Bay Chesapeake Bay History
Formed 12,000 years ago when the lastgreat ice sheet melted,
filling the ancientSusquehanna River. Our current coastline is
approx. 70 milesmore inland than the original shoreline. The FIRST
incarnation of the bay area wascreated by a meteorite. The PRESENT
day Chesapeake Bay wasformed from the last ice age. Chesapeake Bay
Statistics
The largest estuary in N. America.(2500 sq mi) 200 mi. long and 30
mi. wide Over 15 million live in the Chesapeakes watershed,
whichspreads across six states: Virginia, West Virginia,
Maryland,Delaware, Pennsylvania, New York and Washington D.C
principle rivers 400 lesser streams and creeks Has more than 4,600
miles of tidal shoreline The bay hosts nearly 350 species of
finfish and almost 175species of shellfish. The Watershed of the
Bay
Def.-An area of land that is drained by ariver or other body of
water. Six states make up the Ches. Bay watershed:
1.Virginia 2.New York 3.Pennsylvania 4.Maryland 5.Delaware 6.West
Virginia Main Rivers of the Bay There are 5 main rivers of the
shore:
1.James River 2.York River 3.RappahannockRiver 4.Potomac River
5.Susquehanna River The Rivers of the Bay Rivers on the
westernshore are generally largerthan those on the easternshore.
The eastern shore ischaracterized bymarshlands and support avariety
of waterfowl. 52% of the baysfreshwater comes from theSusquehanna
River (mainriver of the bay) Depth of the Bay The bay is very
shallow.
The average depth is only 20 feet. The deepest spot is near
Annapolis, MD andis approximately 180 ft. deep. The bays
world-famous oyster and soft- shelled clam harvests are due to the
amountof suitable shallow water of the bay. Seasons of the Bay:
Spring
A resurgence of activity; migratory speciessuch as fish and crabs
move toward thewarming shallows from deeper parts of theocean.
Shads and herrings move upstream to spawn. Invertebrates begin to
grow and reproduce. Seasons: Spring to Summer
Many fish enter the bay to feed on theabundant schools of smaller
fishes such asanchovies and menhaden. Seasons: Fall and
Winter
Species begin to migrate out of the bay. Activity and growth
decline. In winter months, many animals seek thedeeper areas of the
bay for warmth. How Salty is the Water? Salinity increasesgradually
downstream(towards the ocean). Midway downstream it is12 ppt (about
that ofthe ocean). Salinity also increasesfrom the surface to
thebottom.(2-3 ppt saltier) Salty water is heavier so itsinks below
the less saltywater. Zones of the Bay Zone 1 tidal freshwater Zone
2
slightly brackish tomoderately salty - upper zone is 1-10 ppt lower
zone is ppt Zone 3 salinities 18ppt to oceansalinities of 30+ ppt -
many oceanic animals livehere as well as estuarinespecies Salinity
Determines.
No matter what the habitat a beach,marsh, intertidal flat
SALINITYdetermines the kind of species that livethere.