Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993
The recruitment process for Brazilian sardine (Sardinella brasiliensis) from 1977 to 1993 was investigated by taking into account the effects of spawning stock biomass (SSB), the intensity of the wind and the sea surface temperature (SST). Nonparametric models were applied. Best fits resulted from r...
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| Format: | Article |
| Language: | English |
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Consejo Superior de Investigaciones Científicas
2004-09-01
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| Series: | Scientia Marina |
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| Online Access: | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/391 |
| _version_ | 1831539188078477312 |
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| author | Silvio Jablonski Luiz Fernando Loureiro Legey |
| author_facet | Silvio Jablonski Luiz Fernando Loureiro Legey |
| author_sort | Silvio Jablonski |
| collection | DOAJ |
| description | The recruitment process for Brazilian sardine (Sardinella brasiliensis) from 1977 to 1993 was investigated by taking into account the effects of spawning stock biomass (SSB), the intensity of the wind and the sea surface temperature (SST). Nonparametric models were applied. Best fits resulted from relating recruitment to a combination of SSB and Ekman transport. Transformation of Ekman transport is nearly dome-shaped, with lower and upper limits of 520 and 700 kg s-1 m-1 respectively. Fitting explained 94% of recruitment variability. Regions of maximum values in the transformations were for predictors related to wind, such as wind stress and turbulence index, whose limits were respectively 0.035-0.045 N m-2 and 30-45 m3 s-3. These values correspond approximately to winds of 3.0-4.5 m s-1. SST transformations also follow an apparent dome-shaped curve optimising around 24.75 and 25.5ºC. Inclusion of SST as a third predictor variable led to the loss of the dome-shaped relationship, as shown by the transformations with two predictor variables. Biomass curves are almost logarithmic, their critical point oscillating around 200,000-250,000 t, below which value the stock becomes more dependent on recruitment. The biomass range is greater than previous estimates. |
| first_indexed | 2024-12-16T23:36:48Z |
| format | Article |
| id | doaj.art-6a2258f50d5849369e2465f13bb10033 |
| institution | Directory Open Access Journal |
| issn | 0214-8358 1886-8134 |
| language | English |
| last_indexed | 2024-12-16T23:36:48Z |
| publishDate | 2004-09-01 |
| publisher | Consejo Superior de Investigaciones Científicas |
| record_format | Article |
| series | Scientia Marina |
| spelling | doaj.art-6a2258f50d5849369e2465f13bb100332022-12-21T22:11:44ZengConsejo Superior de Investigaciones CientíficasScientia Marina0214-83581886-81342004-09-0168338539810.3989/scimar.2004.68n3385387Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993Silvio Jablonski0Luiz Fernando Loureiro Legey1Universidade do Estado do Rio de Janeiro, Departamento de OceanografiaPrograma de Planejamento Energético, COPPE, UFRJThe recruitment process for Brazilian sardine (Sardinella brasiliensis) from 1977 to 1993 was investigated by taking into account the effects of spawning stock biomass (SSB), the intensity of the wind and the sea surface temperature (SST). Nonparametric models were applied. Best fits resulted from relating recruitment to a combination of SSB and Ekman transport. Transformation of Ekman transport is nearly dome-shaped, with lower and upper limits of 520 and 700 kg s-1 m-1 respectively. Fitting explained 94% of recruitment variability. Regions of maximum values in the transformations were for predictors related to wind, such as wind stress and turbulence index, whose limits were respectively 0.035-0.045 N m-2 and 30-45 m3 s-3. These values correspond approximately to winds of 3.0-4.5 m s-1. SST transformations also follow an apparent dome-shaped curve optimising around 24.75 and 25.5ºC. Inclusion of SST as a third predictor variable led to the loss of the dome-shaped relationship, as shown by the transformations with two predictor variables. Biomass curves are almost logarithmic, their critical point oscillating around 200,000-250,000 t, below which value the stock becomes more dependent on recruitment. The biomass range is greater than previous estimates.http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/391environmental variablesnonparametric modelsrecruitmentsardinellasoutheastern brazil |
| spellingShingle | Silvio Jablonski Luiz Fernando Loureiro Legey Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 Scientia Marina environmental variables nonparametric models recruitment sardinella southeastern brazil |
| title | Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 |
| title_full | Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 |
| title_fullStr | Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 |
| title_full_unstemmed | Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 |
| title_short | Quantifying environmental effects on the recruitment of the Brazilian sardine (Sardinella brasiliensis), 1977-1993 |
| title_sort | quantifying environmental effects on the recruitment of the brazilian sardine sardinella brasiliensis 1977 1993 |
| topic | environmental variables nonparametric models recruitment sardinella southeastern brazil |
| url | http://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/391 |
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