Lagoa dos Patos (, , ; English: ''Ducks' Lagoon'') is the largest

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into '' coastal lagoons'' (or ''barrier lagoons ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and the largest coastal lagoon in South America. It is located in the state of

Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a state in the southern region of Brazil. It is the fifth-most-populous state and the ninth largest by area. Located in the southernmost part of the country, Rio Grande do Sul is border ...

, southern Brazil. It covers an area of , is long and has a maximum width of . Lagoa dos Patos is separated from the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

by a

sandbar In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. ...

about wide. The Jacuí-

Guaíba Guaíba is a city located in the Metropolitan Porto Alegre of Porto Alegre, in the Brazilian state of Rio Grande do Sul. The city is on the shores of the Guaíba Lake. History In the current territory of the municipality of Guaíba there hav ...

and

Camaquã River The Camaquã River () is a river of Rio Grande do Sul state in southern Brazil. The delta of the river, where it empties into the Lagoa dos Patos, is protected by the Camaquã State Park, created in 1975. See also *List of rivers of Rio Grande ...

s empty into it, while the navigable

São Gonçalo Channel The São Gonçalo Channel () is a navigable channel connecting two large coastal lagoons, Lagoa Mirim and Lagoa dos Patos, in the state of Rio Grande do Sul in southern Brazil. At its eastern end, it separates the municipalities of Rio Grande to ...

, which enters Lagoa dos Patos near the town of

Pelotas Pelotas () is a Brazilian city and municipality (''município''), the third most populous in the southern state of Rio Grande do Sul. It is located 270 km (168 mi) from Porto Alegre, the state's capital city, and 130 km (80.8& ...

, connects Lagoa dos Patos to

Lagoa Mirim Lagoon Mirim (Portuguese, ) or Merín (Spanish, ) is a large estuarine lagoon which extends from southern Rio Grande do Sul state in Brazil into eastern Uruguay. Lagoa Mirim is separated from the Atlantic Ocean by a sandy, partially barren isthm ...

to the south. The Rio Grande, at the south end of Lagoa dos Patos, forms the outlet to the Atlantic. This lagoon is evidently the remains of an ancient depression in the coastline shut in by sand bars built up by the combined action of wind and current. The shallow lagoon is located at sea level and its waters are affected by the tides, normally they are

brackish 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 ...

only a short distance above the Rio Grande outlet, but this can vary a lot. In droughts and favorable winds, sea water can be carried up to almost the entire lagoon. The lagoon's largest and most fertile island is the

Ilha dos Marinheiros Ilha dos Marinheiros ( "Island of the Sailors") is an island located in the south part of a lagoon named Lagoa dos Patos, located in the municipality of Rio Grande, in the state of Rio Grande do Sul, Brazil. It is situated on the west bank o ...

, which is located near the eastern shore. The island is geopolitically part of the municipality of

Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...

. The lagoon hosts a rich biodiversity, including fresh- and brackish water fish, and water birds such as

black-necked swan The black-necked swan (''Cygnus melancoryphus'') is a species of waterfowl in tribe Cygnini of subfamily Anserinae.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the bir ...

coscoroba swan The coscoroba swan (''Coscoroba coscoroba'') is a species of waterfowl in subfamily Anserinae of the family Anatidae.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the bi ...

and

Chilean flamingo The Chilean flamingo (''Phoenicopterus chilensis'') is a species of large flamingo at closely related to the American flamingo and the greater flamingo, with which it was sometimes considered conspecific. The species is listed as near threatened ...

. Top predators from ocean ecosystem, notably

common bottlenose dolphin The common bottlenose dolphin or Atlantic bottlenose dolphin (''Tursiops truncatus'') is a wide-ranging marine mammal of the family Delphinidae. The common bottlenose dolphin is a very familiar dolphin due to the wide exposure it gets in captiv ...

s, can sometimes be seen at Lagoa dos Patos and exceptionally

southern right whale The southern right whale (''Eubalaena australis'') is a baleen whale, one of three species classified as right whales belonging to the genus ''Eubalaena''. Southern right whales inhabit oceans south of the Equator, between the latitudes of 20 ...

s are found at the Rio Grande outlet. ISS-61 Lagos dos Patos, Brazil

Towns and cities on coast

São José do Norte São José do Norte is a municipality in the state of Rio Grande do Sul, Brazil. As of 2020, the estimated population was 27,721. See also *List of municipalities in Rio Grande do Sul This is a list of the municipalities in the state of Rio ...

São Lourenço do Sul São Lourenço do Sul is a Brazilian municipality in the state of Rio Grande do Sul. The municipality had 43,111 inhabitants in the last Census (2010). Its population in 2020 was estimated in 43,540 inhabitants. It is located at the west bank of ...

* Tapes

References

Patos Patos is a municipality of the state of Paraíba in the Northeast Region of Brazil. It is classified by the Brazilian Institute of Geography and Statistics as a sub-regional center A. It is located in the Espinharas River valley, surrounded b ...

Landforms of Rio Grande do Sul {{RioGrandedoSul-geo-stub