Interconnected Lagoons by Brazil-Uruguay Border: Lagoa dos Patos and Lagoa Mirim31.1S 51.4W
Visible near the shoreline in the upper part of this image is the Lagoa dos Patos (meaning Lagoon of the Ducks), the second largest lagoon in Latin America and the biggest in Brazil. It is located in the state of Rio Grande do Sul, southern Brazil.
The lagoon is 174 miles (280 km) long, has a maximum width of 44 miles (70 km), and a total area of 3,803 sq. mi. (9,850 km). It is separated from the Atlantic Ocean by a sandbar about 5 miles (8 kilometers) wide. The navigable São Gonçalo Channel, which enters Lagoa dos Patos near the town of Pelotas, connects Lagoa dos Patos to Lagoa Mirim to the south.
Lagoa Mirim (or Laguna Merín in 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 isthmus.
Lagoa Mirim is about 108 miles (174 km) long by 6 to 22 miles (35 km) wide. It is more irregular in outline than its larger neighbor to the north, Lagoa dos Patos, and discharges into the latter through São Gonçalo Channel. Lagoa Mirim has no direct connection to the Atlantic, but the Rio Grande, a tidal channel about 24 miles (39 km) long which connects Lagoa dos Patos to the Atlantic, affords an entrance to the navigable inland waters of both lagoons and several small ports.