The Brazilian Coastline
Brazil is a privileged country as its territorial extension and location, has a total area of 8,514,876 km square, with a coastline with more than 7000 km long continuous line. The landscape of the Brazilian coast is diverse, consisting of dunes, islands, reefs, rocky coasts, bays, estuaries, swamps and falesias. The region is populated by a huge variety of animals, among them are: dolphins, whales, 800 types of fish, birds, and a variety of vegetables. The most accepted division of brazilian coast is: Litoral amazônico (Amazon coast) – is the coastal region of northern Brazil. Extends from Oiapoque River (AP) to the Parnaíba Delta (between the states of Maranhão and Piauí). The coastline Amazon offers an extensive plain covered by mangroves and marshes, and habitat of various species of fish and birds. Litoral nordestino (Northeastern coast) - the area extends from the Parnaiba Delta to the Reconcavo Baiano, with a length of approximately three thousand kilometers. Its landscape features sand dunes, falesias and mangroves, the climate is pleasant, with high temperatures. Southeast coast – extends from the Reconcavo to the border between the states of São Paulo and Paraná. It has the highest population density of Brazil. South Coast - corresponds to the coast of Paraná, Santa Catarina and Rio Grande do Sul; is characterized by mangroves, falesias and by a continuous strip of beach.
Brazilian Lagoons - along the Brazilian coast are remarkably diffuse coastal lagoons, particularly in the states of Rio de Janeiro and Rio Grande do Sul. The lagoons show a primary productivity comparable to that of estuarine environments and provide many important resources for exploitation by man (fisherie activities, production of macrophytes for food, fertilizer, handicrafts and tourism). The primary production attributed to macrophytes and periphyton is relatively more important than that attributed to phytoplankton. Macrophytes produce residue and increase the heterogeneity of the environment and thus, a greater diversity of macroinvertebrates. In the northern region of the state of Rio de Janeiro, the lagoons have an important social and economic function due to fishing (mainly fish and crustaceans), which is a form of economic livelihood for many local families. These lagoons are also used as areas for recreational purposes. Their origin is linked to the formation of the River Paraíba do Sul delta and is based on fluvial deposits of marine sand occurred in the Quaternary geological era. This type of aquatic ecosystem proved to be highly productive due to the characteristics such as low water and continuous input of dissolved and particulate organic matter from the land. The characteristics of the lagoons and their intrinsic hydrochemical dynamic are directly related to the relative influence of continental and marine waters received. The presence of shallow water and winds allows large variations in terms of materials presence and influences the movement of the water column, thereby enhancing the interaction between the pelagic and benthic compartments. The heterogeneity of morphometric and geomorphologic dynamics observed among neotropical lagoons, is an important aspect, which creates a wide range of ecological gradients and microhabitat, essential for sustaining biodiversity, local or global.
The Northeast region
The brazilian Northeast comprises 9 states: Alagoas, Bahia, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Sergipe and represents 18,26% of the brazilian territory. The Northeast Region of Brazil has several settings regarding the natural aspects of the main elements of nature such as relief, vegetation, climate, hydrography. According to these variations, the region was regionalized and divided into sub-regions, they are the forest zone (“zona da mata” - tropical climate, high temperatures and high rainfall), the middle-northern (“meio-norte” - transition area between the equatorial climate and semi-arid and between savanna and other vegetation, like Cerrado and the Amazon rainforest), rural (“agreste” - between the tropical rain forest and “sertão”, has characteristics ranging from tropical forest, “caatinga” and vegetation of the region dry and hot) and “sertão” (predominantly semi-arid tropical climate, temperatures are high with two well defined seasons, one dry and one wet, however, the rainy season has only three months and long dry spells).
Rio Grande do Norte - RN
The territory of Rio Grande do Norte is located in Northeastern Brazil, is limited to the states of Ceará and Paraíba and by the Atlantic Ocean. The vegetation consists of mangrove areas, a coastal strip of tropical forest and savanna. The coast and the western portion have a tropical climate, whereas the center is semiarid. The territory of RN extends to the Atol das Rocas (Rocas Atoll – approximately 260km northeast from the coastline), a reef formation on a submarine mountain rock substrate, with an area of some 7,5 km2. During high tide only two sandy islands with a maximum height of 3 m above sea level and some isolated calcareous formations, the “rocas”, stand above water. During the low tide, the reef ring of the atoll is exposed, consisting of a natural wall some 1,5 m high and bordered by sandbanks.
Rio Grande do Norte and Ceará are the brazilian's major exporters of shrimp. The local agriculture is based on the sugar cane, maize, coconut, cassava and melon. The state is responsible for 95% of the brazilian salt production; also, is the largest producer of petroleum in land and one of the major supplier of natural gas to the Northeast.
References
http://whc.unesco.org
http://www.mundoeducacao.com.br/
Attayde ,J. L., Bozelli, R. L., 1999. Environmental heterogeneity patterns and predictive models of chlorophyll a in a Brazilian coastal lagoon. Hydrobiologia 390: 129–139
Henriques-de-Oliveira, C., Baptista, DF. and Nessimian, JL., 2007. Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil. Braz. J. Biol., 67(1): 73-80
http://viagem.uol.com.br/ultnot/2010/11/04/bucolica-e-deserta-galinhos-no-rio-grande-do-norte-ainda-e-desconhecida-da-grande-maioria-dos-turistas.jhtm
http://www.webventure.com.br/destinoaventura/rn/galinhos
http://www.praiasecia.com.br/informacao/view/Rio-Grande-do-Norte/Praias-de-Macau/Praia-Diogo-Lopes/
http://www.idema.rn.gov.br/
http://www.pipa.com.br/lagoa_guarairas
http://luislealpipabrasil.blogspot.it/2012/11/a-verdade-sobre-lagoa-guarairas-tibau.html
Lagoons may be clustered together on particular stretches of coasts, where they are dependent on local physical processes, such as sediment transport systems. Such clusters have been considered particularly important for the conservation of lagoon structure and function. Some lagoon types found in this area, are rare elsewhere in Europe. They are a priority habitat type.
The water in coastal lagoons can vary in salinity from brackish (owing to dilution of seawater by freshwater) to hypersaline (i.e. more salty than seawater as a result of evaporation). The plant and animal communities of lagoons vary according to the physical characteristics and salinity regime of the lagoon, and consequently there are significant differences between sites. Although, compared to other marine habitats, there is usually only a limited range of species present, they are especially adapted to the varying salinity regimes of lagoons and some are restricted to lagoon habitats. The vegetation may include Fucus ceranoides, beds of eelgrass Zostera spp., tasselweed Ruppia spp., and pondweeds Potamogeton spp., or stoneworts such as foxtail stonewort Lamprothamnium papulosum. In more rocky lagoons, communities of fucoid wracks Fucus spp., sugar kelp Laminaria saccharina, and red and green algae are also found. The fauna is often characterised by mysid shrimps and other small crustaceans, worms that burrow into the sediment, molluscs, and some fish species. Species that are particularly found in lagoons and consequently have restricted distributions in the UK include starlet sea anemone Nematostella vectensis, lagoon sandworm Armandia cirrhosa, lagoon sand-shrimp Gammarus insensibilis and foxtail stonewort L. papulosum.
Coastal lagoons are areas of shallow, coastal salt water, wholly or partially separated from the sea by sandbanks, shingle or, less frequently, rocks. Lagoons show a wide range of geographical and ecological variation; five main sub-types have been identified in the UK, on the basis of their physiography, as meeting the definition of the Annex I habitat type (Jackson and McLeod 2000).
These are separated completely from the sea or estuary by a barrier of rock or sediment. Seawater enters by limited groundwater seepage or by over-topping of the sea barrier. Salinity is variable but often low. Isolated lagoons are often transient features with a limited lifespan due to natural processes of infilling and coastal erosion.
These are normally separated from the sea by shingle banks. Seawater entersby percolating through the shingle or occasionally by over-topping the bank (e.g. in storms). The water level shows some variation with tidal changes, and salinity may vary. Since percolation lagoons are normally formed by natural processes of sediment transport, they are relatively transient features, which may be eroded and swept away over a period of years or decades or may become infilled by movement of the shingle bank.
Water in silled lagoons is retained at all states of the tide by a barrier of rock (the ‘sill’). There is usually little tidal rise-and-fall. Seawater input is regular (i.e. on most tides) and although salinity may be seasonally variable, it is usually high, except where the level of the sill is near to high tide level. These lagoons are restricted to the north and west of Scotland and may occur as sedimentary basins or in bedrock (where they are called ‘oban’). Muddy areas are dominated by filamentous green algae, amongst which may be colonies of rare charophytes, such as foxtail stonewort Lamprothamnium papulosum. There may be beds of tasselweed Ruppia spp. and, in the deeper most stable lagoons, eelgrass Zostera marina.
Sluiced lagoons are formed where the natural movement of water between the lagoon and the sea is modified by artificial structures, such as a culvert under a road or valved sluices. Communities present in sluiced lagoons vary according to the type of substrate and salinity, but may resemble those of silled lagoons.
Seawater enters lagoonal inlets on each tide and salinity is usually high, particularly at the seaward part of the inlet. Larger examples of this sub-type may have a number of different basins, separated by sills, and demonstrate a complete gradient from full salinity through brackish to freshwater. This salinity gradient significantly increases the habitat and species diversity of the sites in which it occurs. (3)