Eastern Brazil marine ecoregion

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Eastern Brazil marine ecoregion
Ilha da Pedra Furada (51055351611).jpg
Ilha da Pedra Furada
Eastern Brazil marine ecoregion.png
Marine ecoregion boundaries (red line)
Ecology
Realm Tropical Atlantic
Province Tropical Southwestern Atlantic
Geography
Country Brazil
Currents Brazil Current

The Eastern Brazil marine ecoregion covers the coastal marine environment along the middle of the east coast of Brazil. The ecoregion extends south from the Bay of All Saints (about 15 degrees south latitude) to Cabo Frio (about 23 degrees south latitude) just east of the city of Rio de Janeiro. The Brazil Current enters from the east, feeding warm subtropical water to the south along the coast. The influence of the tropical waters leaves the ecoregion relatively oligotrophic (nutrient poor). The Eastern Brazil ecoregion is one of two coastal marine ecoregions (along with the Northeastern Brazil marine ecoregion) in the Tropical Southwest Atlantic marine province. It is thus part of the Tropical Atlantic realm. [1] [2] [3] . [4]

Contents

Physical setting

The ecoregion reaches out into the Atlantic Ocean for 200–250 miles from the coast. The ecoregion is bounded on the north at the Bay of All Saints, and stretches for 1,000 coastal miles to the south at Cabo Frio, where the ecoregion transitions to the Southeastern Brazil marine ecoregion. The bordering coast is generally low and flat, and characterized by Bahia coastal forests ecoregion, and mangrove forests of the Bahia mangroves ecoregion. [5] The major rivers feeding the Eastern Brazil marine region include the Jequitinhonha, Doce and Paraíba do Sul rivers.

The continental shelf along this coast of Brazil extends about 30 miles out to sea in the north and south, but 130 miles in the middle. The deepest point in the ecoregion overall is −3,264 metres (−10,709 ft), and the average is 113 metres (371 ft). [2]

A prominent underwater feature in the middle of the ecoregion is the Albrohos Shelf, a portion of the continental shelf extending 200 km offshore. Besides supporting extensive coral reef complexes, the Albrohos shelf includes the largest known continuous rhodolith bed in the world, with an estimated area of 20,900 km2. Rhodoliths are calcareous nodules created by Coralline algae, and support diverse benthic communities in a manner similar to shallow coral reefs. [6]

Another prominent underwater feature is the east–west trending Vitória-Trindade Seamount Chain (VTC). The seamounts in the ecoregion are known to support high biodiversity in fish species, but are relatively under-explored. [7] The offshore basins of the ecoregion, from north to south, are the Camamu-Almada Basin, the Jequitinhonha Basin, the Cumuruxatiba Basin, the Mucuri Basin, and the Espirito Santo Basin. Oil and gas exploration and production are underway in the northern two basins. [8]

Currents and climate

The Atlantic South Equatorial Current (SEC) flows directly into the ecoregion from the East, bringing warm water from the South Atlantic Ocean. [9] As the SEC approaches the eastern point of Brazil at Cape São Roque, it splits, with the North Brazil Current (NBC) flowing along the coast to the north and west, and the Brazil Current flowing south along the eastern coast. [10] The Brazil Current is a western boundary current, flowing at a rate averaging 4 Sverdrups (Sv), at a mean speed of 60–100 centimetres per second (1.3–2.2 mph). Surface temperatures range from 22–28.5 °C (71.6–83.3 °F).

Animals / Fish

Biodiversity of the near-shore areas varies with the influence of the coasts - mangroves, sandbanks, and beaches - and also by the nature of the bottoms, which are reefs, gravel and mud. There are a variety of fish, cetaceans, turtles, shrimps and lobsters. A recent study found 25 species of shark and 9 species of rays. [11]

Over 90% of commercial fishing is on the nearshore coast, typically by artisinal (subsistence and traditional) methods. Traditional methods of hook and line fishing, and with gillnets, are employed on small boats seeking drum fish (family Sciaenidae ). Small shrimp trawlers and lobster boats also operate in the coastal waters, with some evidence that use of nets by lobster fishers is causing harm to the bottom for other species. [12] [11] In the south, along Rio de Janeiro state, the artisinal beach fishery uses large canoes and seine nets to catch migrating schools of bluefish, mullets and bonitos. [12]

Offshore, the industrial fisheries of the region are mostly employ hook-and-line methods rather than trawlers due to the narrow coastal shelf, rocky bottom, and deep canyons. The commercial fishery is centered on rockfish, sharks and tuna. [12]

Conservation status

Many of the terrestrial protected areas on the coast have marine components, such that about 8% of the ecoregion is protected, including: [2]

As of 2013, only 2% of the Albrohos Shelf, with its Mesophotic coral reefs, was in a "no-take" protected area. [6]

Related Research Articles

The Global 200 is the list of ecoregions identified by the World Wide Fund for Nature (WWF), the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". For example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.

<span class="mw-page-title-main">Agulhas Bank</span> Broad southernmost part of the African continental shelf

The Agulhas Bank is a broad, shallow part of the southern African continental shelf which extends up to 250 km (160 mi) south of Cape Agulhas before falling steeply to the abyssal plain.

<span class="mw-page-title-main">Marine ecosystem</span> Ecosystem in saltwater environment

Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.

<span class="mw-page-title-main">Tweed-Moreton</span> Marine biogeographic region in Australia

Tweed–Moreton, also known as the Central Eastern Shelf Transition, is a marine biogeographic region of eastern Australia.

<span class="mw-page-title-main">Outline of oceanography</span> Hierarchical outline list of articles related to oceanography

The following outline is provided as an overview of and introduction to Oceanography.

<span class="mw-page-title-main">Fishing industry in the United States</span>

As with other countries, the 200 nautical miles (370 km) exclusive economic zone (EEZ) off the coast of the United States gives its fishing industry special fishing rights. It covers 11.4 million square kilometres, which is the second largest zone in the world, exceeding the land area of the United States.

<span class="mw-page-title-main">Marine ecoregions of the South African exclusive economic zone</span> Geographical regions of similar ecological characteristics

The marine ecoregions of the South African exclusive economic zone are a set of geographically delineated regions of similar ecological characteristics on a fairly broad scale, covering the exclusive economic zone along the South African coast.

The marine protected areas of South Africa are in an area of coastline or ocean within the exclusive economic zone (EEZ) of the Republic of South Africa that is protected in terms of specific legislation for the benefit of the environment and the people who live in and use it. An MPA is a place where marine life can thrive under less pressure than unprotected areas. They are like underwater parks, and this healthy environment can benefit neighbouring areas.

<span class="mw-page-title-main">Marine biodiversity of South Africa</span> Variety of living organisms that live in the seas off the coast of South Africa

The Marine biodiversity of South Africa is the variety of living organisms that live in the seas off the coast of South Africa. It includes genetic, species and ecosystems biodiversity in a range of habitats spread over a range of ecologically varied regions, influenced by the geomorphology of the seabed and circulation of major and local water masses, which distribute both living organisms and nutrients in complex and time-variable patterns.

The East African coral coast is a marine ecoregion along the eastern coast of Africa. It extends along the coasts of Kenya, Tanzania, and northern Mozambique, from Lamu in Kenya to Angoche in Mozambique. It adjoins the Northern Monsoon Current Coast ecoregion to the north, and the Bight of Sofala/Swamp Coast ecoregion to the south.

The Bight of Sofala/Swamp Coast is a marine ecoregion along the eastern coast of Africa, characterized by extensive mangrove swamps and coastal wetlands. It extends along the coast of Mozambique, from Angoche to the Bazaruto Archipelago. It adjoins the East African coral coast ecoregion to the north, and the Delagoa ecoregion to the south.

The Northern Monsoon Current coast is a marine ecoregion along the eastern coast of Africa. It extends along a portion of the coasts of Somalia and Kenya, from south of Lamu in Kenya to north of Mogadishu in Somalia. It adjoins the Central Somali coast ecoregion to the north, and the East African coral coast ecoregion to the south.

The Biodiversity of South Africa is the variety of living organisms within the boundaries of South Africa and its exclusive economic zone. South Africa is a region of high biodiversity in the terrestrial and marine realms. The country is ranked sixth out of the world's seventeen megadiverse countries, and is rated among the top 10 for plant species diversity and third for marine endemism.

<span class="mw-page-title-main">Guianan marine ecoregion</span> Tropical marine ecoregion

The Guianan marine ecoregion stretches along the middle of the northeast coast of South America, touching Venezuela, Guyana, Suriname and French Guiana. It extends about 200 miles offshore, with the warm Guianan Current moving east-to-west through the region. This current brings in fresh, turbid waters from the mouth of the Amazon River to the east. As the current exits the ecoregion to the west it contributes an estimated 70% of the waters of the Caribbean Sea. A very large oil field has been recently discovered in the Guyana-Suriname Basin of the ecoregion. The Guianan is one of two ecoregions in the North Brazil Shelf province, a Large marine ecosystem (LME). The Guianan is thus part of the larger Tropical Atlantic realm.

<span class="mw-page-title-main">Amazonia marine ecoregion</span> Tropical marine ecoregion

The Amazonia marine ecoregion covers the coastal marine environment off the mouth of the Amazon River on the continental shelf of Brazil. The warm North Brazil Current moves east-to-west across the river's outlet, carrying turbid, fresh water to the northwest towards the Caribbean Sea. The Amazonia is one of two ecoregions in the North Brazil Shelf province, a large marine ecosystem (LME). It is thus part of the Tropical Atlantic realm.

<span class="mw-page-title-main">Northeastern Brazil marine ecoregion</span> Tropical marine ecoregion

The Northeastern Brazil marine ecoregion covers the coastal marine environment around the Northeast Region of Brazil. The marine ecoregion extends from the mouth of the Parnaíba River in the west around the eastern point of the Brazilian mainland and south to the Bay of All Saints. The warm South Equatorial Current feeds warm tropical water into the region from the east. The Northeastern Brazil ecoregion is one of two coastal marine ecoregions in the Tropical Southwest Atlantic marine province. It is thus part of the Tropical Atlantic realm.

<span class="mw-page-title-main">Southeastern Brazil marine ecoregion</span> Tropical marine ecoregion

The Southeastern Brazil marine ecoregion covers the warm coastal waters to 250 miles offshore of southeastern Brazil, from the latitude of Rio de Janeiro in the north to Florianópolis in the south. Marine diversity is supported by local upwellings in the north and the inflow of the Brazil Current. The region is one of transition from a tropical to a warm temperate environment. The marine ecoregion is one of four coastal marine ecoregions in the Warm Temperate Southwestern Atlantic marine province. It is thus part of the Temperate South America realm. .

<span class="mw-page-title-main">Rio Grande marine ecoregion</span> Tropical marine ecoregion

The Rio Grande marine ecoregion covers the waters offshore of the southern Brazilian states of Rio Grande do Sul and Santa Catarina. The ecoregion stretches along 500 miles of sandy beach coast, and 200 miles out to sea. The warm Brazil Current flows south through the region in parallel with the coast. The continental shelf is smooth and flat, with the bottom mostly sand and mud. Overfishing is a problem, but marine life in recent years has benefited from measures such as a 2018 ban on motorized shrimp trawler fishing within 12 miles of the Rio Grande do Sul coast. The Rio Grande ecoregion is one of four coastal marine ecoregions in the Warm Temperate Southwestern Atlantic marine province. It is thus part of the Temperate South America realm. .

<span class="mw-page-title-main">Uruguay - Buenos Aires Shelf marine ecoregion</span>

The Uruguay - Buenos Aires Shelf marine ecoregion covers waters offshore of Uruguay, the mouth of the Rio de la Plata), and Buenos Aires Province of Argentina. It has an area of 258,490 square kilometres (99,800 sq mi) and a coastline of 1,300 kilometres (810 mi). Marine biodiversity is very high due to the mixing of currents, the mixing of fresh and salt water, the mixing of temperatures, and the broad, shallow continental shelf. Large amounts of nutrients arrive from the northwest flowing Malvinas Current and from the continental runoff of the Rio de la Plata. Aside from high populations of fish there are colonies of marine mammals, sea turtles, and seabirds.

References

  1. ↑ Spalding, MD; Fox, Helen; Allen, Gerald; Davidson, Nick. "Marine Ecoregions of the World: A Bioregionalization of Coastal and Shelf Areas". Bioscience. Retrieved June 30, 2022.{{cite web}}: CS1 maint: multiple names: authors list (link)
  2. 1 2 3 "Eastern Brazil". Digital Observatory for Protected Areas (DOPA). Retrieved September 9, 2022.
  3. ↑ "Eastern Brazil". MarineRegions.org. Retrieved September 9, 2022.
  4. ↑ "East Brazil Shelf". One Shared Ocean. Retrieved September 9, 2022.
  5. ↑ "Setting Geographic Priorities for Marine Conservation in Latin America and the Caribbean" (PDF). The Nature Conservancy. Retrieved June 30, 2022.
  6. 1 2 M Soares, T Tavares, P Carneiro (11 December 2018). "Mesophotic fishes of the Abrolhos Shelf, the largest reef ecosystem in the South Atlantic". Diversity and Distributions. Biodiversity Review: ddi.12846. doi: 10.1111/ddi.12846 . S2CID   91675512 . Retrieved February 19, 2023.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ↑ H T Pinheiro (2015). "Fish Biodiversity of the Vitória-Trindade Seamount Chain, Southwestern Atlantic: An Updated Database". PLOS ONE. PLoS ONE 10(3): e0118180. 10 (3): e0118180. doi: 10.1371/journal.pone.0118180 . PMC   4349783 . PMID   25738798.
  8. ↑ "Brazilian player keeping its stake in Petrobras-operated gas field". Offshore Energy. 22 April 2022. Retrieved February 19, 2023.
  9. ↑ "South Equatorial Current". University of Miami. Retrieved September 9, 2022.
  10. ↑ "Brazil Current". University of Miami. Retrieved September 9, 2022.
  11. 1 2 TCM Souza (2008). "Characterization of small-scale fisheries in the Camamu-Almada basin, southeast state of Bahia, Brazil". Brazilian Journal of Biology. 68 (4): 711–719. doi:10.1590/S1519-69842008000400005. hdl: 11449/20470 . PMID   19197488 . Retrieved February 19, 2023.
  12. 1 2 3 "Artisanal fisheries in Brazil" (PDF). FFLCH-NUPAUB. Retrieved February 10, 2023.
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