Chesapeake Bay 59473 226043912 2008-07-16T16:03:05Z Rogerd 205136 Disambiguate [[Skipjack]] to [[Skipjack (boat)]] using [[:en:Wikipedia:Tools/Navigation_popups|popups]] [[Image:Chesapeakelandsat.jpeg|thumb|right|250px|The Chesapeake Bay - [[Landsat]] photo]] The '''Chesapeake Bay''' is the largest [[estuary]] in the [[United States]]. It lies off the [[Atlantic Ocean]], surrounded by [[Maryland]] and [[Virginia]]. The Chesapeake Bay's [[drainage basin|watershed]] covers {{convert|64299|sqmi|km2|0|lk=on}} in the [[District of Columbia]] and parts of six states: [[New York]], [[Pennsylvania]], [[Delaware]], [[Maryland]], [[Virginia]], and [[West Virginia]].<ref name="fs102-98">{{cite web |url=http://pubs.usgs.gov/fs/fs102-98/ |title=Fact Sheet 102-98 - The Chesapeake Bay: Geologic Product of Rising Sea Level |publisher=U. S. Geological Survey |date=1998-11-18 |accessdate=2008-01-13 }}</ref> More than 150 rivers and streams drain into the Bay. The Chesapeake Bay is about 200 [[mile]]s (300&nbsp;[[kilometre|km]]) long, from the [[Susquehanna River]] in the north to the Atlantic Ocean in the south. At its narrowest point between [[Kent County, Maryland|Kent County's]] Plum Point (near Newtown) and the [[Harford County, Maryland|Harford County]] shore near Romney Creek, the Bay is 2.8 miles (4.5&nbsp;km) wide; at its widest point, just south of the mouth of the [[Potomac River]], it is 30 miles (50&nbsp;km) wide. Total shoreline for the Bay and its tributaries is 11,684 miles (18,804 km), and the surface area of the bay and its major tributaries is {{convert|4479|sqmi|km2|0}}. The bay is spanned in two places. The [[Chesapeake Bay Bridge]] crosses the bay in Maryland from Sandy Point (near [[Annapolis]]) to [[Kent Island, Maryland|Kent Island]]; the [[Chesapeake Bay Bridge-Tunnel]] in Virginia connects [[Virginia Beach, Virginia|Virginia Beach]] to [[Cape Charles, Virginia|Cape Charles]]. The word ''Chesepiooc'' is an [[Algonquian]] word commonly believed to mean "Great Shellfish Bay;" however, a reconstruction of Virginian Algonquian implies that the word may mean something like "Great Water" or it might just be the name of a village at the mouth of the bay.<ref>{{cite news|title=A Dead Indian Language Is Brought Back to Life |last=Farenthold|first=David A.|work=The Washington Post|date=2006-12-12|page=A1|url=http://www.washingtonpost.com/wp-dyn/content/article/2006/12/11/AR2006121101474_2.html?nav=rss_email/components|accessdate=2007-03-19}}</ref> ==Geology== [[Image:Chesapeake Bay Bridge.jpg|thumb|250px|The [[Chesapeake Bay Bridge]].]] The Chesapeake Bay is the [[ria]], or drowned valley, of the Susquehanna, meaning that was where the river flowed when sea level was lower. It is not a [[fjord]], as the [[Laurentide Ice Sheet]] never reached as far south as the northernmost point on the bay. The Bay was formed starting about 10,000 years ago when rising sea levels at the end of the last ice age flooded the Susquehanna river valley.<ref name="fs102-98"/> The Bay's geology, its present form and its very location have also been affected by a [[bolide]] [[impact event]] at the end of the [[Eocene]] (about 35.5 million years ago), forming the [[Chesapeake Bay impact crater]]. Parts of the bay, especially the [[Calvert County, Maryland]] coastline, are lined by cliffs composed of deposits from receding waters millions of years ago. These cliffs, generally known as [[Calvert Cliffs State Park|Calvert Cliffs]], are famous for their [[fossils]], especially fossilized [[shark]] teeth, which are commonly found washed up on the beaches next to the cliffs. [[Scientists' Cliffs]] is a beach community in [[Calvert County]] named for the desire to create a retreat for scientists when the community was founded in 1935. <ref>{{cite web| url = http://http://www.scientistscliffs.org/HTML/FAQs/FAQs.htm | title = FAQ | publisher = Scientists Cliffs community | accessdate = 2008-05-08}}</ref> Much of the bay is quite shallow. At the point where the Susquehanna River flows into the bay, the average depth is {{convert|30|ft|m|0|}}, although this soon diminishes to an average of {{convert|10|ft|m|0}} from the city of [[Havre de Grace]] for about {{convert|35|mi|km|0}}, to just north of Annapolis. On average, the depth of the bay is 21 [[Foot (unit of length)|feet]] (7 [[metre|meters]]), including tributaries;<ref>{{cite web| url = http://www.cbf.org/site/PageServer?pagename=exp_sub_watershed_geography | title = Geography | publisher = [[Chesapeake Bay Foundation]] | accessdate = 2008-04-21}} Other sources give values of 25 feet (e.g. {{cite web | url = http://www.msa.md.gov/msa/speccol/sc2200/sc2269/html/chartfront.html | title = Charting the Chesapeake 1590-1990 | publisher = Maryland State Archives | accessdate = 2008-04-21}}) or 30 feet deep ({{cite web| url = http://ian.umces.edu/pdfs/iannewsletter1.pdf | title = Healthy Chesapeake Waterways | publisher = [[University of Maryland Center for Environmental Science]] | accessdate = 2008-04-21}})</ref> over 24% of the bay is less than {{convert|6|ft|m|0|abbr=on}} deep. {{Fact|date=September 2007}} The climate of the area surrounding the bay is primarily [[humid subtropical]], with hot, very humid summers and cold to mild winters. Only the area around the mouth of the Susquehanna River is continental in nature, and the mouth of the Susquehanna River and the Susquehanna flats often freeze in winter. It is exceedingly rare for the surface of the bay to freeze in winter, as happened most recently in the winter of 1976-1977.<ref>{{citation | journal = Time | title = The Big Freeze | date = [[1977-01-31]] | url = http://www.time.com/time/magazine/article/0,9171,918620-2,00.html | accessdate = 2007-03-19}}</ref> Since the bay is an estuary, it has fresh water and brackish water. Brackish water has three salinity zones&nbsp;&mdash; oligohaline, mesohaline, and [[polyhaline]]. The fresh water zone runs from the mouth of the Susquehanna River to north [[Baltimore, Maryland|Baltimore]]. The oligohaline zone has very little salt. Salinity varies from 0.5&nbsp;[[Concentration#.22Parts-per.22_notation|ppt]] to 10&nbsp;ppt and freshwater species can survive there. The north end of the oligohaline zone is north Baltimore and the south end is the Chesapeake Bay Bridge. The mesohaline zone has a medium amount of salt and runs from the Bay Bridge to the mouth of the Rapahannock River. the salinity ranges from 10.7&nbsp;ppt to 18&nbsp;ppt. The polyhaline zone is the saltiest zone and some of the water can be as salty as sea water. It runs from the mouth of the [[Rappahannock River]] to the mouth of the bay. The salinity ranges from 18.7&nbsp;ppt to 36&nbsp;ppt. (36&nbsp;ppt is as salty as the ocean.) ==History== [[Lucas Vásquez de Ayllón]] was the first [[Europe]]an to explore and map the Chesapeake Bay. He established a short-lived [[Spain|Spanish]] mission settlement, "San Miguel de Guadalupe", in the early 16th century near the future site of [[Jamestown, Virginia|Jamestown]]. [[Captain John Smith]] of [[England]] explored and mapped the bay between 1607 and 1609. The "[[Captain John Smith Chesapeake National Historic Trail]]", the United States' first-ever all-water [[National Historic Trail]], was created in July 2006. The bill passed by voice vote in the House of Representatives and by unanimous consent in the Senate.<ref>{{cite web |title=H.R. 5466 <nowiki>[109th]</nowiki> Captain John Smith Chesapeake National Historic Trail Designation Act |url=http://www.govtrack.us/congress/bill.xpd?bill=h109-5466 |publisher=GovTrack.us |accessdate=2007-12-16 }}</ref> The Chesapeake Bay was the site of the [[Battle of the Chesapeake]] in 1781, during which the [[France|French]] fleet defeated the [[Royal Navy]] in the decisive naval battle of the [[American Revolutionary War]]. Today, the [[Calvert Cliffs Nuclear Power Plant]] uses water from the bay to cool its reactor. The bay is also known for the [[Chesapeake Bay Retriever]], a [[dog breed]] developed in this area. ==Watershed== [[Image:Chesapeake Bay Watershed.gif|thumb|200px|The Chesapeake Bay Watershed]] The largest rivers flowing into the bay, from north to south, are: * [[Susquehanna River]] * [[Patapsco River]] * [[Chester River]] * [[Choptank River]] * [[Patuxent River]] * [[Potomac River]] * [[Rappahannock River]] * [[Nanticoke River]] * [[York River (Virginia)|York River]] * [[Back River (Virginia)|Back River]] * [[James River (Virginia)|James River]] ==Fishing industry== [[Image:Skipjack EPA.PNG|thumb|left|200px|A [[Skipjack (boat)|skipjack]], part of the [[oyster#Oyster fishing|oystering]] fleet in Maryland]] [[Image:ChesapeakeFishingBoat.jpg|thumb|right|200px|A charter fishing boat on the Chesapeake Bay]] The bay was once known for its great seafood production, especially [[blue crab]]s, [[clam]]s and [[oyster]]s. The plentiful oyster harvests led to the development of the [[Skipjack (boat)|skipjack]], the state boat of Maryland, which is the only remaining working boat type in the [[United States]] still under sail power. Other characteristic bay area workboats include:<ref>{{cite web |title=Chesapeake Bay Workboats| url = http://www.baygateways.net/workboats.cfm |publisher=[http://www.baygateways.net/ Chesapeake Bay Gateway Network]| accessdate = 2007-03-19}}</ref> * the [[log canoe]] * the [[pungy]] * the [[bugeye (boat)|bugeye]] * the [[Chesapeake Bay deadrise]] Today, the body of water is less productive than it used to be, because of [[surface runoff|runoff]] from [[urban area]]s (mostly on the [[Western Shore]]) and farms (especially on the [[Maryland Eastern Shore|Eastern Shore]]), overharvesting, and [[invasive species|invasion of foreign species]]. The bay though, still yields more [[fish]] and [[shellfish]] (about 45,000 short [[ton]]s or 40,000 [[tonne]]s yearly) than any other estuary in the United States. The bay is famous for its [[rockfish]], also known as [[striped bass]]. Once on the verge of extinction, rockfish have made a significant comeback due to legislative action that put a moratorium on rockfishing, which allowed the species to repopulate. Rockfish are now able to be fished in strictly controlled and limited quantities. Oyster farming is a growing industry for the bay to help maintain the bay's productivity as well as a natural effort for filtering impurities in the bay in an effort to reduce the disastrous effects of man-made [[water pollution|pollution]]. In 2005, local governments began debate on the introduction to certain parts of the bay of a species of Asian [[oyster]], to revive the lagging shellfish industry. ==Deteriorating environmental conditions== [[Image:ChesapeakeTidalWetlands.jpg|thumb|right|250px|Tidal [[wetlands]] of the Chesapeake Bay]] In the 1970s, the Chesapeake Bay contained one of the planet's first identified [[marine dead zone]]s, where [[Hypoxia (environmental)|hypoxic]] waters were so depleted in oxygen they were unable to support life, resulting in massive fish kills. Large [[algae]] blooms, nourished by the runoff of farm and industrial [[wastewater|waste]] throughout the watershed, prevent sunlight from reaching the bottom of the bay. The resulting loss of [[aquatic plant|aquatic vegetation]] has depleted the habitat for many of the bay's animal creatures. One particularly harmful algae is ''[[Pfiesteria piscicida]]'', which can affect both fish and humans. The depletion of oysters due to overharvesting and damaged habitat has had a particularly harmful effect on the quality of the bay. The bay's oyster industry has also suffered from two diseases: [[Oyster#MSX|MSX]] and [[Oyster#Dermo|Dermo]].<ref>{{cite web |url=http://www.vims.edu/env/research/shellfish/ |title=Research &ndash; Shellfish Diseases |publisher=Virginia Institute of Marine Science |date=2007-03-16 |accessdate=2008-02-22 }}</ref> Oysters serve as natural water filters, and their decline has further reduced the water quality of the bay. Water that was once clear for metres is now so [[turbidity|turbid]] that a wader may lose sight of his feet before his knees are wet. Efforts of federal, state and local governments, working in partnership through the [[Chesapeake Bay Program]], and the [[Chesapeake Bay Foundation]] and other nonprofit environmental groups, to restore or at least maintain the current [[water quality]] have had mixed results. One particular obstacle to cleaning up the bay is that much of the polluting substances arise far upstream in [[tributary|tributaries]] lying within states far removed from the bay itself. It has been estimated that in pre-colonial times, oysters could filter all the water in the Bay in about 3.3 days, but in 1988 it was calculated that depletion of oyster beds had increased this time to 325 days.<ref>{{cite web|url=http://habitat.noaa.gov/restorationtechniques/public/habitat.cfm?HabitatID=2&HabitatTopicID=11|title=Oyster Reefs: Ecological importance|publisher=US National Oceanic and Atmospheric Administration |accessdate=2007-11-06}}</ref> Efforts at oyster farming is one method Marylanders are using to clean up the pollution. ==Tourism== The Chesapeake Bay is still a main feature for tourists who visit Maryland and Virginia each year. Fishing, crabbing, swimming, boating and sailing are still extremely popular activities enjoyed on the waters of the Chesapeake Bay. This tourist attraction has a major impact on Maryland's economy. ==See also== {{commonscat|Chesapeake Bay}} *[[Delmarva Peninsula]] *[[Dead zone (ecology)]] *[[Chesapeake (novel)|Chesapeake]], a novel by author [[James A. Michener]] *[[Chessie (sea monster)]] *[[The National Estuarine Research Reserve System]] *[[List of islands in Maryland]] (with the islands in the Bay) *[[Coastal and Estuarine Research Federation]] ==References== {{reflist}} ==Further reading== *Cleaves, E.T. et al. (2006). ''Quaternary geologic map of the Chesapeake Bay 4º x 6º quadrangle, United States'' [Miscellaneous Investigations Series; Map I-1420 (NJ-18)]. Reston, VA: U.S. Department of the Interior, U.S. Geological Survey. *Phillips, S.W., ed. (2007). ''Synthesis of U.S. Geological Survey science for the Chesapeake Bay ecosystem and implications for environmental management'' [U.S. Geological Survey Circular 1316]. Reston, VA: U.S. Department of the Interior, U.S. Geological Survey. ==External links== * [http://www.savethechesapeake.org/ Saving The Chesapeake Bay] * [http://www.cbf.org/ Chesapeake Bay Foundation] * [http://www.chesapeake.org/ Chesapeake Research Consortium] * [http://www.acb-online.org/ Alliance for the Chesapeake Bay] * [http://www.chesapeakebay.net/ Chesapeake Bay Program] * [http://www.bayjournal.com/ Chesapeake Bay Journal] * [http://www.baygateways.net/ Chesapeake Bay Gateways Network] * [http://ccmp.chesapeake.org/ Chesapeake Community Modeling Program] * [http://www.roadstothefuture.com/Chesapeake_Bay_Bridge.html Chesapeake Bay Bridge (near Annapolis, MD)] * [http://www.cbbt.com/ Chesapeake Bay Bridge-Tunnel] * [http://www.mdsg.umd.edu/CB/index.html Maryland Sea Grant] * [http://www.scientistscliffs.org Scientist's Cliffs] * [http://www7.nationalgeographic.com/ngm/0506/feature2 National Geographic- Saving The Chesapeake] * [http://www.nationalgeographic.com/chesapeake National Geographic- Exploring The Chesapeake Then and Now] * [http://www.ngm.com/jamestown National Geographic Magazine Jamestown/Werowocomoco Interactive] * [http://cbf.typepad.com/johnsmith/ John Smith Water Trail Blog - Musings and Meanders on the Chesapeake Bay] * [http://www.nps.gov/nero/josm/ Captain John Smith Chesapeake National Historic Water Trail] * [http://www.cbayfloors.com/chesapeake_bay.html Sailing the Chesapeake Bay] * [http://www.nutrientnet.org NutrientNet], an online nutrient trading tool developed by [http://www.wri.org the World Resources Institute], designed to address water quality issues in the Chesapeake Bay and elsewhere. See also the [http://pa.nutrientnet.org PA NutrientNet] website designed for Pennsylvania's nutrient trading program. {{Maryland}} {{Virginia}} {{Maryland waters}} {{coord|37|02|N|76|03|W|display=title|region=US_type=waterbody_scale=3000000}} [[Category:Chesapeake Bay| ]] [[Category:Chesapeake Bay Watershed]] [[Category:Intracoastal Waterway]] [[Category:Estuaries of Maryland]] [[Category:Estuaries of Virginia]] [[Category:Marine ecoregions]] [[Category:Bays of Virginia]] [[Category:Bays of Maryland]] [[ca:Badia de Chesapeake]] [[cs:Chesapeake (zátoka)]] [[da:Chesapeake Bay]] [[de:Chesapeake Bay]] [[es:Bahía de Chesapeake]] [[fa:خلیج چساپیک]] [[fr:Baie de Chesapeake]] [[he:מפרץ צ'ספיק]] [[sw:Hori ya Chesapeake]] [[hu:Chesapeake-öböl]] [[nl:Chesapeakebaai]] [[ja:チェサピーク湾]] [[no:Chesapeake Bay]] [[pl:Zatoka Chesapeake]] [[pt:Baía de Chesapeake]] [[ru:Чесапикский залив]] [[fi:Chesapeakenlahti]] [[vi:Vịnh Chesapeake]] [[uk:Чесапікська затока]] [[zh:切萨皮克湾]]