The Mobile–Tensaw River Delta is the largest

river delta A river delta is a landform shaped like a triangle, created by deposition (geology), deposition of sediment that is carried by a river and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, res ...

and

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

Alabama (We dare defend our rights) , anthem = "Alabama (state song), Alabama" , image_map = Alabama in United States.svg , seat = Montgomery, Alabama, Montgomery , LargestCity = Huntsville, Alabama, Huntsville , LargestCounty = Baldwin County, Al ...

. It encompasses approximately in a area and is the second largest delta in the

contiguous United States The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...

. This large river delta is approximately 45 miles long and averages 8 miles wide, being 16 miles wide at its widest point. It covers approximately 300 square miles. Of its 260,000 acres, 20,000 acres consist of open water, 10,000 acres of marsh, 70,000 acres of swamp; and more than 85,000 acres of bottomland forest. It drains an area of about 44,000 sq miles, which includes 64% of Alabama and small portions of Georgia and Mississippi. The delta's northernmost point is the confluence of the Tombigbee and

rivers and follows a southerly direction that ultimately opens into the head of

Mobile Bay Mobile Bay ( ) is a shallow inlet of the Gulf of Mexico, lying within the state of Alabama in the United States. Its mouth is formed by the Fort Morgan Peninsula on the eastern side and Dauphin Island, a barrier island on the western side. The ...

through the

Mobile Mobile may refer to: Places * Mobile, Alabama, a U.S. port city * Mobile County, Alabama * Mobile, Arizona, a small town near Phoenix, U.S. * Mobile, Newfoundland and Labrador Arts, entertainment, and media Music Groups and labels * Mobile ( ...

, Tensaw,

Apalachee The Apalachee were an Indigenous people of the Southeastern Woodlands, specifically an Indigenous people of Florida, who lived in the Florida Panhandle until the early 18th century. They lived between the Aucilla River and Ochlockonee River,Bobby ...

, Middle, Blakeley, and

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Cana ...

rivers near the

Battleship Parkway Battleship Parkway, commonly referred to locally and in the media as the "Causeway", is a long causeway that carries US 90 and US 98 eastbound across Mobile Bay from the Bankhead Tunnel on Blakeley Island in Mobile, Alabama to Spanish Fort, ...

. It is contained within sections of Baldwin,

Clarke Clarke is a surname which means "clerk". The surname is of English and Irish origin and comes from the Latin . Variants include Clerk and Clark. Clarke is also uncommonly chosen as a given name. Irish surname origin Clarke is a popular surname i ...

, Monroe, and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

counties.South Alabama Regional Planning Commission
/ref>

Environment and ecology

The Mobile–Tensaw delta is ecologically important and includes a wide variety of habitats, including mesic

flood plains A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

cypress Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the ...

- gum

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

s, tidal

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estua ...

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es, bottomland forests and submersed grass beds. As one of the most biologically diverse regions in both Alabama and the United States, it is home to 126 species of fish, 46 mammals, 69 reptiles, 30 amphibians, and at least 300 species of bird, including more than 110 which nest in the region. The delta's considerable biodiversity has led to it being described as an "American

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

" by naturalist

E. O. Wilson Edward Osborne Wilson (June 10, 1929 – December 26, 2021) was an American biologist, naturalist, entomologist and writer. According to David Attenborough, Wilson was the world's leading expert in his specialty of myrmecology, the study of an ...

Margaret Renkl Margaret Renkl (born October 1961) is an American writer and contributing opinion writer for the ''New York Times'' who lives in Nashville, Tennessee. Renkl is the author of ''Late Migrations: A Natural History of Love and Loss'', and two other bo ...

has written about the delta and its vulnerability to

coal ash Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when de ...

pollution from the James M. Barry Electric Generating Plant upstream along the

Mobile River The Mobile River is located in southern Alabama in the United States. Formed out of the confluence of the Tombigbee and Alabama rivers, the approximately river drains an area of of Alabama, with a watershed extending into Mississippi, Georg ...

Natural history

The delta lies in a river valley which began forming several million years ago. Many separate inland streams joined as they flowed southward across land which was once covered by the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

. By the end of the last major

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

(approximately 18,000 years ago), when the sea level was much lower and Alabama's coastline was about south of its present location, the waterways of the delta valley extended much farther than their current-day southern termination at the head of Mobile Bay. As the ice age ended and global temperatures increased, sea levels began to rise again to their present-day level."Mobile–Tensaw Delta"
Encyclopedia of Alabama

History

Humans inhabited the delta region at least as far back as 5,000 years ago. During the Mississippian periodically time, people of the

Pensacola culture The Pensacola culture was a regional variation of the Mississippian culture along the Gulf Coast of the United States that lasted from 1100 to 1700 CE. The archaeological culture covers an area stretching from a transitional Pensacola/Fort Walton ...

built earthen

mound A mound is a heaped pile of earth, gravel, sand, rocks, or debris. Most commonly, mounds are earthen formations such as hills and mountains, particularly if they appear artificial. A mound may be any rounded area of topographically higher el ...

s along

Bottle Creek A bottle is a narrow-necked container made of an impermeable material (such as glass, plastic or aluminium) in various shapes and sizes that stores and transports liquids. Its mouth, at the bottling line, can be sealed with an internal stopp ...

and the Tensaw River. During the late prehistoric period, other peoples moved into the area, including the Taensas (Tensaw), the

Creek A creek in North America and elsewhere, such as Australia, is a stream that is usually smaller than a river. In the British Isles it is a small tidal inlet. Creek may also refer to: People * Creek people, also known as Muscogee, Native Americans ...

, and the

Choctaw The Choctaw (in the Choctaw language, Chahta) are a Native American people originally based in the Southeastern Woodlands, in what is now Alabama and Mississippi. Their Choctaw language is a Western Muskogean language. Today, Choctaw people are ...

. In the 16th century, the area was visited by Spanish forces. French explorers arrived in the last years of the 17th century, eventually settling colonial Mobile in 1702 at Twenty-seven Mile Bluff on the Mobile River. During the

Creek War The Creek War (1813–1814), also known as the Red Stick War and the Creek Civil War, was a regional war between opposing Indigenous American Creek factions, European empires and the United States, taking place largely in modern-day Alabama ...

, Red Stick Creeks attacked

Fort Mims Mims or MIMS may refer to: Acronyms * Mandarin Immersion Magnet School, Houston, Texas * MediCiti Institute of Medical Sciences, a medical college near Hyderabad, India * Membrane-introduction mass spectrometry * Monthly Index of Medical Special ...

near the confluence of the Alabama and Tombigbee rivers in August 1813, where they killed most of the mixed-blood Tensaw and Lower Town Creeks, intermarried whites, slaves, and nearly 275 militia. The

schooner A schooner () is a type of sailing vessel defined by its rig: fore-and-aft rigged on all of two or more masts and, in the case of a two-masted schooner, the foremast generally being shorter than the mainmast. A common variant, the topsail schoon ...

'' Clotilda'' arrived in the Delta on July 7, 1860, carrying 103 enslaved West Africans captured in

Dahomey The Kingdom of Dahomey () was a West African kingdom located within present-day Benin that existed from approximately 1600 until 1904. Dahomey developed on the Abomey Plateau amongst the Fon people in the early 17th century and became a region ...

, and was

scuttled Scuttling is the deliberate sinking of a ship. Scuttling may be performed to dispose of an abandoned, old, or captured vessel; to prevent the vessel from becoming a navigation hazard; as an act of self-destruction to prevent the ship from being ...

to prevent being prosecuted under the

Act Prohibiting Importation of Slaves The Act Prohibiting Importation of Slaves of 1807 (, enacted March 2, 1807) is a United States federal law that provided that no new slaves were permitted to be imported into the United States. It took effect on January 1, 1808, the earliest dat ...

. It was the last

slave ship Slave ships were large cargo ships specially built or converted from the 17th to the 19th century for transporting slaves. Such ships were also known as "Guineamen" because the trade involved human trafficking to and from the Guinea coast ...

to enter the United States via the

Atlantic slave trade The Atlantic slave trade, transatlantic slave trade, or Euro-American slave trade involved the transportation by slave traders of enslaved African people, mainly to the Americas. The slave trade regularly used the triangular trade route and i ...

. After the

Emancipation Proclamation The Emancipation Proclamation, officially Proclamation 95, was a presidential proclamation and executive order issued by United States President Abraham Lincoln on January 1, 1863, during the Civil War. The Proclamation changed the legal sta ...

and the Thirteenth Amendment, many of the descendants of the ''Clotilda'' would establish the neighborhood of

Africatown Africatown, also known as AfricaTown USA and Plateau, is a historic community located three miles (5 km) north of downtown Mobile, Alabama. It was formed by a group of 32 West Africans, who in 1860 were included in the last known illegal shi ...

. The last important battle of the

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...

took place at the fortified town of Blakeley, located on the edge of the delta. A railroad line to connect Mobile to Montgomery, now part of the

CSX CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. The railroad operates approximately 21,000 route miles () of track. ...

system, opened across the delta in 1872. In the mid-1920s, the

Causeway A causeway is a track, road or railway on the upper point of an embankment across "a low, or wet place, or piece of water". It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden causeways is the Sweet Tra ...

was built across the lowest part of the delta, connecting the western and eastern shores of Mobile Bay. Later,

I-65 Interstate 65 (I-65) is a major north–south Interstate Highway in the central United States. As with most primary Interstates ending in 5, it is a major crosscountry, north–south route, connecting between the Great Lakes and the Gulf ...

and

I-10 Interstate 10 (I-10) is the southernmost cross-country highway in the American Interstate Highway System. I-10 is the fourth-longest Interstate in the United States at , following I-90, I-80, and I-40. This freeway is part of the originally pl ...

were constructed to span different parts of the area. An area of 190,000 acres of the Delta was designated as a

National Natural Landmark The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best ...

in 1974, and four sites within the Delta are also listed on the National Register of Historic Places.

Conservation Issues

The Mobile–Tensaw River Delta and the adjacent Mobile estuary make up one of the largest wet land ecosystems in the United States, which is why protecting its wide range of biodiversity is a top priority for conservators. According to the Forever Wild ranking system, the Mobile-Tensaw Delta is of their top priorities for protection. The Alabama Department of Conservation and Natural Resources (ADCNR) Game & Fish Division has also listed the Mobile-Tensaw Delta as one of their highest priorities for inclusion into the state Wildlife Management Area System. The delta is one of 327 watersheds (of the 2,100 in the United States) to be deemed as being of irreplaceable value to conserving populations of all freshwater fish and mussel species at risk. Conservators’ wide range of obstacles include hydrological alterations from man-made developments, stream pollution, the effects of upstream dams on stream flow, and effects of exotic invasive plant and animal species. The construction of the causeway in the 1920s is considered one of the most significant man-made obstructions to the delta. The causeway restricts sediment and water exchange with Mobile Bay resulting in an immensely higher sedimentation rate. The loss of hydrological connectivity between the Delta and Mobile Bay reduced the salinity of the surrounding rivers and bay. Several species of fish, crustaceans, shellfish, and plant communities have been altered as a result of reduced salinity. It is important to recognize that human activates resulting in upstream pollution within the Mobile River Basin have profound impacts on the Mobile-Tensaw Delta. Such pollution can include sediments, trace elements, metals, and pesticides draining from the basin upstream. Trace elements detected in fish tissue collected from sites throughout the Mobile River Basin suggest that aluminum, boron, copper, iron, manganese, selenium, strontium, and zinc are the trace elements that are most prevalent in the water. Upstream dams are put into place for most commonly the purposes of power generation, navigation, and flood control. Dams distort the natural hydrological flow by either physically restricting movement of wildlife or by creating large areas of inhospitable habitat. In both cases, populations are isolated, which can have detrimental effects on reproduction and natural migration. The Claiborne Lock and Dam is the largest dam upstream of the Mobile water basin located in Monroe County, Alabama. Exotic invasive plant and animal species have permanently altered he Mobile–Tensaw River Delta’s ecology. Both invasive plants and animals pose a threat to the native populations of wildlife that call the Mobile Delta home. Some of the most common non-native invasive plant species to conquer the delta include Eurasian watermilfoil, hydrilla, water hyacinth, and common salvinia. The most common invasive invertebrates include the Amazonian apple snails, Asiatic clams, and subtropical water fleas. Invasive fishes include common carp and grass carp. The invasive species that poses the largest threat to the entire ecosystem are wild swine. They are so detrimental to our entire Alabama ecosystem because they will eat almost any type of plant or animal materials, including agricultural crops, food discarded by humans, carrion, small mammals, birds, turtles, snakes, and amphibians. Humans are considered the only significant threat to the hog population, which is why they are one of the only hunted animals in the state that are not monitored by a season for hunting.

Recreation

Boating Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether Motorboat, powerboats, Sailing, sailboats, or man-powered vessels (such as rowing and paddle boats), focused on the travel itself, as well as sp ...

and

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...

are popular in the Mobile Delta. Boat ramps and water access points are abundant throughout the area. The

Bartram Canoe Trail The Bartram Canoe Trail is a system of canoe and kayak water trails in the Mobile–Tensaw River Delta of Alabama. Named for explorer and naturalist William Bartram, the 200-mile-long trail system is one of the longest in the United States. It inc ...

provides a system of waterways by which boaters may explore the delta. The area is known for its excellent

bird watching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, ...

.Alabama Coastal Bird Watching
/ref>

Hunting Hunting is the human activity, human practice of seeking, pursuing, capturing, or killing wildlife or feral animals. The most common reasons for humans to hunt are to harvest food (i.e. meat) and useful animal products (fur/hide (skin), hide, ...

is also a common pastime. Most of the Delta is very shallow water. To access these areas, airboats, canoes, kayaks or other small craft are typically used.

References

External links

U.S. Geological Survey Map Mobile-Tensaw Delta Wildlife Management Area
at the U.S. Geological Survey Map Website. Retrieved February 2, 2023.
U.S. Geological Survey Map W. L. Holland Wildlife Management Area
at the U.S. Geological Survey Map Website. Retrieved February 2, 2023. {{DEFAULTSORT:Mobile-Tensaw River Delta Protected areas of Baldwin County, Alabama Protected areas of Mobile County, Alabama National Natural Landmarks in Alabama River deltas of the United States Mobile Bay Landforms of Baldwin County, Alabama Landforms of Mobile County, Alabama Estuaries of Alabama Wetlands of Alabama Alabama placenames of Native American origin