Yearly variation in primary productivity of marine phytoplankton from Cabo Frio (RJ, Brazil) region

Gonzalez‐Rodriguez, Eliane

doi:10.1007/bf00016855

Cited by 26 publications

(11 citation statements)

References 27 publications

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“…Nutrient-rich, cold SACW is widespread on the shelf in the South Brazil Bight during austral summer. Variations in upwelling-favorable winds can bring it to the surface (Castro & Miranda, 1998), leading to high productivity in pulsed cycles of upwelling and relaxation that last days to weeks (Valentin et al, 1987;Gonzalez-Rodriguez et al, 1992, Gonzalez-Rodriguez, 1994. During both sets of summer experiments in the northern part of the Bight, temperature and salinity indicated that SACW was indeed present in deeper waters, but did not come any closer to the surface than about 20 m. During our summer 2003 experiments, for example (Fig.…”

Section: Discussionmentioning

confidence: 70%

Microzooplankton grazing of phytoplankton in a tropical upwelling region

et al. 2006

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We measured grazing by herbivorous zooplankton ( < 200 lm fraction) in coastal and slope regions of the South Brazil Bight. Using the dilution technique, we performed nine experiments during the austral summer, when nutrientrich South Atlantic Central Water is present on the shelf, and five during winter. These experiments provide the first estimates of microzooplankton grazing in the western South Atlantic Ocean. Model II regression showed a strong relationship between phytoplankton intrinsic growth rates and grazing, with a slope of 0.64 (±0.28; 95% confidence interval) indicating that microzooplankton grazing could account for the majority of phytoplankton mortality. Both phytoplankton growth and microzooplankton grazing were higher during the summer upwelling season, compared to winter. For the two experiments that were conducted in oligotrophic slope water, grazing accounted for >80% of phytoplankton production. A comparison of incubations with and without added inorganic nutrients showed no consistent stimulation of phytoplankton growth (slope of enriched versus unenriched treatments not significantly different from 1). Estimates from microscopic counts of heterotrophic organisms >10 lm indicated that copepod nauplii comprised the largest share of the microzooplankton biomass (mean 62.4 ± 5.8% SE). Grazing estimates were not correlated with microzooplankton biomass, whether or not nauplii were included, suggesting that most of the grazing was done by nano-sized zooplankton.

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Section: Discussionmentioning

confidence: 70%

Microzooplankton grazing of phytoplankton in a tropical upwelling region

et al. 2006

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“…The heating and mixture of SACW favor diatom and nanophytoplankton production (GONZALEZ-RODRIGUEZ, 1994;TENEMBAUM, 1995;GUENTHER et al, 2008). Also, the heterotrophic/autotrophic ratio and the viral abundance are negatively correlated with temperature (PEREIRA et al, 2010).…”

Section: Physical-biological Interactions: Ecological Consequences Ofmentioning

confidence: 99%

“…Nutrient concentrations are one of the main factors causing variability in the production of upwelling environments (GONZALEZ-RODRIGUEZ; MAESTRINI, 1984;ARNTZ et al, 2006;PENNINGTON et al, 2006;BAKUN;PATTI et al, 2008). SACW has a higher temperature and lower nutrient concentrations at Cabo Frio as compared to the water of the Benguela system, since nitrate values fall from 30 µM in the Benguela system (BROWN; FIELD, 1986) to as little as 18 µM in the Cabo Frio region (GONZALEZ-RODRIGUEZ et al, 1992).…”

Section: Physical-biological Interactions: Ecological Consequences Ofmentioning

confidence: 99%

Biophysical interactions in the Cabo Frio upwelling system, southeastern Brazil

et al. 2012

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A B S T R A C TThe rising of cold water from deeper levels characterizes coastal upwelling systems. This flow makes nutrients available in the euphotic layer, which enhances phytoplankton production and growth. On the Brazilian coast, upwelling is most intense in the Cabo Frio region (RJ). The basic knowledge of this system was reviewed in accordance with concepts of biophysical interactions. The high frequency and amplitude of the prevailing winds are the main factor promoting the rise of South Atlantic Central Water, but meanders and eddies in the Brazil Current as well as local topography and coast line are also important. Upwelling events are common during spring/summer seasons. Primary biomass is exported by virtue of the water circulation and is also controlled by rapid zooplankton predation. Small pelagic fish regulate plankton growth and in their turn are preyed on by predatory fish. Sardine furnishes an important regional fish stock. Shoreline irregularities define the embayment formation of the Marine Extractive Reserve of Arraial do Cabo making it an area with evident different intensities of upwelled water that harbors high species diversity. Consequently, on a small spatial scale there are environments with tropical and subtropical features, a point to be explored as a particularity of this ecosystem. R E S U M OOs sistemas costeiros de ressurgência são caracterizados pela ascensão de águas frias que tornam os nutrientes disponíveis na camada eufótica para o crescimento e aumento da produção fitoplanctônica. No Brasil, a região do Cabo Frio (RJ) é o principal sistema de ressurgência costeira. O objetivo desse artigo foi revisar o atual conhecimento desse sistema através dos conceitos sobre interações biofísicas. A ascensão da Água Central do Atlântico Sul ocorre devido à alta frequência e amplitude dos ventos, à presença de meandros e vórtices na Corrente do Brasil, além da topografia local e da linha de costa. Os eventos de ressurgência são comuns durante os períodos de primavera/verão e a biomassa primária é exportada devido à circulação da água, sendo também controlada pela rápida predação zooplanctônica. Os pequenos peixes pelágicos regulam o crescimento do plâncton e são consumidos pelos peixes predadores, resultando em um importante estoque pesqueiro regional. A irregularidade da costa define as enseadas do Cabo Frio, na Reserva Extrativista Marinha do Arraial do Cabo, apresentando distintas influências das águas ressurgidas e resultando em grande diversidade de espécies. Consequentemente, ambientes com características tropicais e subtropicais são observados dentro de uma pequena escala espacial, o que constitui uma particularidade desse ecossistema.

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“…Mesotrophic or eutrophic conditions are mainly local, depending on either land-based sources Ovalle et al, 1999;Dittmar and Lara, 2001) or upwelling processes (Carbonel and Valentin, 1999;Gonzalez-Rodriguez, 1994). Estuarine and coastal areas near major urban settlements are the most eutrophic (Contador and Paranhos, 1996;Jorcin, 2000), with untreated sewage discharge being one of the main sources of nutrients to coastal areas (Kjerfve et al, 1997;Carreira and Wagener, 1998).…”

Section: Nutrification Along the Brazilian Coastmentioning

confidence: 99%