South Brazil Shelf large marine ecosystem

Source: NOAA

Introduction

caption Location of the South Brazil Shelf Large Marine Ecosystem. (Source: NOAA)

The South Brazil Shelf Large Marine Ecosystem (LME) is characterized by its mixed climate. The Brazil Current flows parallel to this coast and is an offshoot of the South Equatorial Current. The continental shelf is wide, reaching 220 kilometers (km) in some areas. This LME has a composite structure of environmental conditions, with high water temperatures at least in some periods of the year. It is subjected to relatively intense shelf edge and wind-driven upwellings of nutrient rich waters in the summer (see Hubold, 1980a,b; and Bakun and Parrish, 1991). It is controlled by shelf topography. It has material sources from land. It sustains moderately diverse food webs and higher production than the East Brazil LME to the north. LME book chapters and articles pertaining to the South Brazil Shelf include Bakun, 1993, and Ekau and Knoppers, 2003.

Productivity

For a map of proposed ecosystem boundaries along the Brazilian coast, see Ekau and Knoppers, 2003. For more information on coast topography, water masses and currents, sediments and plankton characteristics, see Ekau and Knoppers, 2003. See also Evans and Signorini (1985), Peterson and Stramma (1991), and Castro and Miranda (1998). The LME is an area of microtides and is influenced by the outflow of the Patos and La Plata estuaries. The South Brazil Shelf LME is considered a Class II, moderately high productivity (150-300 gC/m2/yr) ecosystem based on SeaWiFS global primary productivity estimates. Food webs are moderately diverse, but productivity is extremely high in the southern portion, and especially in the South Brazilian Bight. Productivity decreases towards the north. Primary production is marked by spatial and seasonal variability. Rates are higher during the summer, with the upwelling of South Atlantic Central Water. For information on primary production rates in the coastal areas off of Sao Paulo and Parana, see Brandini, 1990. For the coastal areas of the Rio Grande, see Ciotti et al., 1995. For the influence of warm tropical waters, see Bakun, 1999.

Fish and Fisheries

caption Catch by species in the South Brazil Shelf LME. (Source: NOAA)

The commercial species in this LME include sardines, oysters, shrimp, anchovy and hake. The Food and Agriculture Organization (FAO) provides combined data for the South Brazil Shelf LME and part of the East Brazil LME (see FAO, 2003). Clupeoids (herrings, sardines, and anchovies) represent the most important species group in shelf catches, but other groups are also represented (see FAO, 2003). Sardines and mackerels are most important by weight (see Ekau and Knoppers, 2003). The Brazilian sardine (Sardinella brasilinensis) is a warm water species that is mostly confined to the Brazilian Bight, between Cabo Frio and Cabo de Santa Marta Grande (see Bakun, 1993). It spawns during the austral summer, when cool, nutrient-rich South Atlantic Central Water (SACW) penetrates into the coastal areas (see Matsuura, 1998). The Brazilian sardine population has been overfished for several years and has also been affected by some adverse environmental conditions. It declined to a state of collapse in 1986-1987. The nutrient-rich and cool SACW did not penetrate into the near-coastal habitat of the Southeastern Brazilian Bight. For more information on sardine recruitment variability and temperature anomalies in those years, see Bakun, 1993. Catches declined from 230,000 tons a year in the 1980s to 32,000 tons in 1990 (see Ekau and Knoppers, 2003). Sardine catches recovered in 1998 to 82,000 tons, but the stock still seems in poor condition (see FAO, 2000). Skipjack tuna is fished along the shelf edge. For more on demersal fisheries from 1975 to 1994, see Haimovici, 1998. For information on the small-scale hake fishery and on shrimp, see Paiva, 1997. The South Brazilian Bight is very productive and accounts for over 50% of Brazil’s commercial fisheries yield. For more information on fisheries yield and composition, see Ekau and Knoppers, 2003. For information about artisanal and industrial catches in the different states along the Brazilian coastline, see Ekau and Knoppers, 2003. Information on the exploitation of fish stocks is not available for all areas and species. The Global International Waters Assessment (GIWA) has issued a matrix that ranks LMEs according to the sustainable exploitation of fisheries and the predicted direction of future changes. GIWA characterizes the LME as severely impacted in terms of overfishing, excessive by catch and destructive fishing practices. These impacts, however, are thought to be decreasing (see the GIWA web site). Brazilian Fisheries are managed by different regional departments of the Brazilian Institute of Environment and Natural Renewable Resources. For detailed fish catch statistics, see data collected by the University of British Columbia Fisheries Center.

Pollution and Ecosystem Health

Areas of global concern are climate change, biodiversity; and ozone depletion. The Global International Waters Assessment (GIWA) has issued a matrix that ranks LMEs according to pollution. GIWA characterizes the LME as severely impacted in terms of eutrophication with severe economic consequences. These impacts are increasing (see the GIWA web site). Air and water pollution issues stem from the presence of Brazil’s two largest metropolitan areas. Rio de Janeiro, the world’s 10th largest city with a population of 5.3 million, is situated on the coast. Sao Paulo is positioned less than 50 miles inland and has concentrations of petrochemical and fertilizer industries. Moreover, 2.3 million people are concentrated in the Patos Lagoon area, at the northern end of the South Brazil Shelf LME. This major area of agricultural production makes a heavy use of fertilizers and pesticides. These anthropogenic disturbances, the inadequate treatment of sewage, and the degradation of water quality, have an impact on living marine resources and contribute to eutrophication and loss of habitat. The main sources of marine pollution in the LME are linked to land-based activities, especially arising out of urbanization and coastal development, tourism and recreation centers, transport and oil refineries. The development of tourism is affecting coastal ecosystems. Brazilian beaches are contaminated by ship debris, industrial effluents and heavy metals.

Socioeconomics

Artisanal and commercial fishing, tourism, and shipping are important economic activities. Brazil contains the second largest oil reserves in South America after Venezuela, and is striving for self-sufficiency in oil production. The Campos and Santos basins hold the largest Brazilian gas fields. The Pelotas Basin, near Rio, is a potentially rich offshore area, as yet under-explored and under-exploited. The economic slowdowns experienced in this part of Brazil seem to suggest a correlation between economic growth, poverty, and environmental degradation. Ecological problems are deeply rooted in social, political, as well as economic factors. There are major societal and technological challenges in trying to address poverty and reduce the income gap between rich and poor.

Governance:

The South Brazil Shelf LME is bordered by the Brazilian states of Rio de Janeiro, Sao Paulo, Parana, Santa Catarina, and Rio Grande do Sul. Brazil has expended great efforts to assess the state of the living and non-living resources within its Exclusive Economic Zone (EEZ). Some of the requirements for sustainable development include the alleviation of poverty, innovative development strategies, technological improvements and sound conservation policies. The greatest constraints are the lack of harmonized legal instruments and financial mechanisms, as well as discrepancies in the capabilities of national and regional experts and managers. Brazil has an ongoing coastal zone management program (GERCO-PNMA, 1996).

Information on the exploitation of Brazilian fish stocks is not available for all areas and species (see Ekau and Knoppers, 2003). CEPSUL is a regional department of the Brazilian Institute of Environment and Natural Renewable Resources (IBAMA), which covers the coastline from Cape Frio to the Uruguayan border. The South Brazil Shelf LME has one protected area, Lagoa do Peixe, established in 1993 in Rio Grande do Sul. It is an extensive lowland area of salt marshes, coastal sand dunes, lagoons and lakes that provides important staging sites for numerous migrant species of shorebirds and waterfowl.

References 

 Articles and LME Volumes

  • Bakun, A., 1993. The California Current, Benguela Current, and southwestern Atlantic shelf ecosystems: A comparative approach to identifying factors regulating biomass yields. In K. Sherman, L.M. Alexander, and B.D. Gold, eds. Large Marine Ecosystems: Stress, Mitigation, and Sustainability. AAAS Press, Washington, DC. 199-221. ISBN:087168506X
  • Ekau, W. and B. Knoppers, 2003. A review and redefinition of the large marine ecosystems of Brazil. In: K. Sherman and G. Hempel (eds.). Large Marine Ecosystems of the World --Trends in Exploitation, Protection and Research. Elsevier Science. Amsterdam. FAO, 2003. Trends in oceanic captures and clustering of large marine ecosystems—2 studies based on the FAO capture database. FAO fisheries technical paper 435. 71 pages. ISBN: 0444510273.
  • Prescott, J.R.V. 1989. The political division of large marine ecosystems in the Atlantic Ocean and some associated seas. In K. Sherman and L.M. Alexander, eds. Biomass Yields and Geography of Large Marine Ecosystems. AAAS Selected Symposium 111. Westview Press, Boulder CO. 395-442. ISBN: 0813378443.

Other References

  • Alencar-Vilela, M.J.; Castello, J.P. 1993: Population dynamics of the skipjack tuna (Katsuwonus pelamis) fishery off south and southern Brazil in the period 1980-1986. Frente-Marit, 14.
  • Bakun, A.; Parrish, R.H., 1991: Comparative studies of coastal pelagic fish reproductive habitats: the anchovy (Engraulis anchoita) of the southwestern Atlantic. ICES J. mar. Sci., 48: 343-361.
  • Bröckel, K.v.; Meyerhöfer, M., 1999: Impact of the rocks of São Pedro and São Paulo upon the quantity and quality of suspended particulate organic matter. Arch.Fish.Mar.Res. 47(2/3), 223-238.
  • Castro, B.M.; Miranda, L.B., 1998: Physical oceanography of the western Atlantic continental shelf located between 4°N and 34°S. In: Robinson, A.R.; Brink, K.H. (eds.): The Sea, Vol. 11: 209-252, New York, John Wiley & Sons. ISBN: 0674017412.
  • Ciotti, A.M.; Odebrecht, C.; Fillmann, G.; Möller jr., O.O., 1995: Freshwater outflow and subtropical convergence influence on phytoplankton biomass on the southern Brazilian continental shelf. Cont. Shelf Res., 15(14): 1737-1756.
  • Dias-Neto, J.; Mesquita, J.X., 1988: Potencialidade e explotação dos recursos pesqueiros do Brasil. Ciência e Cultura, São Paulo, 40(5): 427-441.
  • Evans, D.L.; Signorini, S.R., 1985: Vertical structure of the Brazil Current. Nature, 315: 48-50.
  • FAO, 1997: Review of the state of world fishery resources: Marine fisheries. 6. Southwest Atlantic. FAO Fisheries Circular No. 920 FIRM/C920, Rome.
  • FAO, 2000:Fishery statistics. FAO yearbook vol 86/1 1998, FAO, Rome.
  • GERCO-PNMA, 1996: Macrodiagnóstico da zona costeira do Brasil na escala da união. - Gerenciamento Costeiro, Programa Nacional do Meio Ambiente, MMA (Ministério do Meio Ambiente,UFRJ, SUJD, LAGEJ, Brasilia: 280 pp.
  • Gordon, A.L., and C.L. Greengrove, 1986. Geostrophic circulation of the Brazil-Falkland confluence. Deep Sea Res., 3: 573-585.
  • Haimovici, M., 1998: Present state and perspectives for the southern Brazil shelf demersal fisheries. Fish. Manage. Ecol., 5(4); 277-289.
  • Hubold, G. 1980 a: Hydrography and plankton off southern Brazil and Rio de la Plata, August - Novermber 1977. Atlântica, 4: 1-22.
  • Hubold, G. 1980 b: Second report on hydrography and plankton off southern Brazil and Rio de la Plata, Autumn cruise: April - June 1978. Atlântica, 4: 23-42.
  • Jablonski, S.; Matsuura, Y., 1985: Estimate of exploitation rates and population size of skipjack tuna off the southeastern coast of Brazil. Bol.-Inst.-Oceanogr.,-Sao-Paulo., 33(1), 29-38.
  • Kjerfre, B.; Lacerda, L.D., 1990: Mangroves of Brazil. In: Lacerda, L.D. (ed.): Conservation and sustainable utilization of mangrove forests in Latin America and Africa regions. Part I - Latin America. ITTO/ISMA Project PD 114/90: 245-271.
  • Knoppers, B.; Kjerfvre, B. 1999: Coastal lagoons of southeast Brazil: Physical and biogeochemical characteristics. In: Perillo, G.M.E; Piccolo, M.C. & Pino-Quivira, M. (eds.):Estuaries of South America. Springer Verlag Berlin: 35-62. ISBN:354065657X
  • Martins, L.R.; Coutinho, P.N., 1981: The Brazilian continental margin. Earth Science Review, 17: 87-107.
  • Matsuura, Y. 1995: Exploração pesqueira. In: Os ecossistemas brasileiras e os principais macrovetores de desenvolvimento: subsídios ao planejamento da gestão ambiental. Programma nacional do meio ambiente, Brasília: 77-89.
  • Matsuura, Y. 1998: Brazilian sardine (Sardinella brasiliensis) spawning in the southeast Brazilian Bight over the period 1976-1993.Rev. bras. oceanogr., 46(1): 33-43.
  • Melo, U.; Summerhayes, C.P.; Ellis, J.P., 1975: Salvador to Vitória, Southeastern Brazil. In: Upper Continental Margin sedimentation off Brazil. Stuttgart: Contribution to Sedimentology 4: 78-116. ISBN: 3510570049.
  • Paiva, M.P. (ed.), 1997: Recursos pesqueiros estuarinos e marinhos do Brasil. Avaliação do potencial sustentável de recursos vivos na zona econômica exclusiva. Universidade Federal do Ceará, Fortaleza: 286 pp.
  • Panouse, M.; Susini, S.M., 1987. Production primaire du phytoplancton. In: Guille, A.; Ramos, J.M. (eds.): Terres Australis et Antarctiques Françaises. Mission de recherche. Les rapports des campagnes a la mer a bord du "Marion Dufresne": 91-107.
  • Peterson, R.G.; Stramma, L., 1991: Upper-level circulation in the South Atlantic Ocean. Prog. Oceanog., 26: 1-73.
  • Pires-Vanin, A.M.S.; Rossi-Wongtschowski, C.L.D.B.; Aidar, E.; Mesquita, H. de S.L.; Soares, L.S.H.; Katsuragawa, M.; Matsuura, Y., 1993: Estrutura e função do ecossistema de plataforma continental do Atlântico Sul brasileiro: síntese dos resultados. Publção esp. Inst. oceanogr., S.Paulo 10: 217-231.
  • Teixeira, C.; Gaeta, S.A., 1991: Contribution of picoplankton to primary production in estuarine, coastal and equatorial waters of Brazil. Hydrobiologia, 209: 117-122.
  • Valentin, J.L.; Monteiro-Ribas, W.M., 1993: Zooplankton community structure on the east-southeast Brazilian continental shelf (18-23°S latitude). Cont. Shelf Res. 13(4): 407-424.
  • Vieira, A.A.H.; Teixeira, C., 198. Excreção de matéria orgânica dissolvida por populações fitoplanctônicas da costa leste e sudeste do Brasil. Bolm. Inst. oceanogr., S. Paulo, 30(1): 9-25.
  • Yesaki, M., 1974. Os recursos de peixes de arrasto ao largo da costa do Brasil. Programa.de Pesquisa e Desenvolvimento Pesqueiro/ Série Documentos Técnicos, Rio de Janeiro, 8: I-II + 1-47.



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(2008). South Brazil Shelf large marine ecosystem. Retrieved from http://www.eoearth.org/view/article/51cbeee97896bb431f69b1d7

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