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| Van der Lingen, C.D.; Kreiner, A.; Fréon, P.. |
| Time-series of condition factor (CF) and gonadosomatic index (GSI) were generated using general linear models (GLM) for sardine Sardinops sagax stocks in the northern and southern Benguela ecosystems over the period 1984–1999. During this period the biomass of sardine in the northern Benguela remained at relatively low levels of <500 000 tons, whereas that of southern Benguela sardine increased 40-fold to 1.3 million tons. The GLMs explained 27 and 45% of the observed variation in CF, and 32 and 28% of the observed variation in GSI, for sardine in the northern and southern Benguela subsystems respectively. Whereas the sardine CF in the northern Benguela remained stable over time, that for the southern Benguela stock declined steadily during the study... |
| Tipo: Journal Contribution |
Palavras-chave: Abstracts; Ecosystems; Sardine fisheries; Ecosystems; Http://aims.fao.org/aos/agrovoc/c_2482. |
| Ano: 2001 |
URL: http://hdl.handle.net/1834/2124 |
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| Kirchner, C. H.; Bartholomae, C. H.; Kreiner, A.. |
| This study attempts to explain the variability in recruitment of sardine in the northern Benguela and to develop potential models by including environmental information to predict recruitment. Two different recruitment and spawner number datasets were available: a VPA-developed dataset, for the period 1952–1987, and data from a simple age-structured model for 1992–2007. In all, four environmental indices were used: the degree of the intrusion of the warm Angola Current into northern Namibia, termed the Angola–Benguela front index; the extent of the upwelling area off central Namibia; average sea surface temperature (SST) over the northern and central Namibian shelf; and wind stress anomalies at Lüderitz as an indicator of upwelling strength. Contrary to... |
| Tipo: Journal Contribution |
Palavras-chave: Currents (water); Upwelling; Sardine fisheries; Environments; Ecosystems; Anomalies; Biomass; Spawning; Recruitment. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/4671 |
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