Fuzzy modelling of chlorophyll production in a Brazilian upwelling system

Pereira, G. C.; Evsukoff, Alexandre G.; Ebecken, Nelson F. F.

doi:10.1016/j.ecolmodel.2009.03.025

Cited by 21 publications

(9 citation statements)

References 16 publications

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“…This approach enables qualitative information consisting of linguistic terms to be used for the quantitative evaluation of target systems that are required for decision making at an ecosystem level. The expert knowledge-based models have been further improved with respect to predictive performance by incorporating optimisation approaches such as heuristic hill-climbing algorithms and genetic algorithms (GAs : Goldberg 1989; see Mouton et al 2008Mouton et al , 2009aMouton et al , b, 2011 for the application of hill-climbing algorithms; see Hiramatsu et al 2003;Van Broekhoven et al 2007;Fukuda and Hiramatsu 2008;Fukuda and Okushima 2008;Fukuda 2009;Pereira et al 2009;Fukuda et al 2011 for the application of GAs). Specifically, fuzzy systems optimised using GAs are called genetic fuzzy systems (Cordon et al 2001;Herrera 2008).…”

Section: Introductionmentioning

confidence: 99%

Abundance versus presence/absence data for modelling fish habitat preference with a genetic Takagi–Sugeno fuzzy system

Fukuda

Mouton

Baets

2011

Environ Monit Assess

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This study compared the accuracy of fuzzy habitat preference models (FHPMs) and habitat preference curves (HPCs) obtained from the FHPMs in order to assess the effect of two types of data [log-transformed fish population density (LOG) and presence-absence (P/A) data] on the habitat preference evaluation of Japanese medaka (Oryzias latipes). Three independent data sets were prepared for each type of data. The results differed according to the data sets and the types of data used. The HPCs showed a similar trend, whilst the degrees of preference were different. The model accuracy also differed according to the data sets used. Although almost no statistical difference was observed, on average, the P/A-based models showed a better performance according to the threshold-independent performance measures, whilst the LOG-based models showed better performance in predicting absence of the fish. These results can be explained partly from the different shapes of HPCs. This case study of Japanese medaka demonstrated the effect of different types of data on habitat preference evaluation. Further studies should build on the present finding and evaluate the effects of data characteristics such as the size of data sets and the prevalence for better understanding and reliable assessment of the habitat for target species.

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Section: Introductionmentioning

confidence: 99%

Abundance versus presence/absence data for modelling fish habitat preference with a genetic Takagi–Sugeno fuzzy system

Fukuda

Mouton

Baets

2011

Environ Monit Assess

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“…In the Cabo Frio system, nitrate is the main limiting nutrient but phosphate and to a lesser degree iron and molybdenum are also important in the regulation of phytoplankton biomass growth (GONZALEZ-RODRIGUEZ, 1991). Chlorophyll a concentrations reported in the main upwelling area of the Cabo Frio region varied between 0.5 and 6.0 mg/m 3 (GONZALEZ-RODRIGUEZ et al, 1992;PEREIRA et al, 2009a) but a value of 21 mg/m3 was observed during a microalgae bloom in the Cabo Frio Embayment. These values are comparable with those found in shelf and coastal areas of the southern and eastern Pacific (MONTECINO et al, 2004;PENNINGTON et al, 2006).…”

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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“…During the colder months (autumn and winter), when upwelling seldom occurs, the temperature profiles are vertically homogeneous and the surface waters are typically oligotrophic (Valentin et al 1987, Gonzalez-Rodriguez et al 1992, Castro & Miranda 1998, Pereira et al 2009). The concentrations of dissolved inorganic nitrogen during the winter were half those measured during the summer, and the concentrations of chl a varied from 5 to 12 mg m −3 (Gonzalez-Rodriguez et al 1992).…”

Section: Introductionmentioning

confidence: 99%