Browsing by Author "Inejih, C. A. O."
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- An application of two techniques for the analysis of short, multivariate non-stationary time-series of Mauritanian trawl survey dataPublication . Erzini, Karim; Inejih, C. A. O.; Stobberup, Kim A.Min/max autocorrelation factor analysis (MAFA) and dynamic factor analysis (DFA) are complementary techniques for analysing short (> 15-25 y), non-stationary, multivariate data sets. We illustrate the two techniques using catch rate (cpue) time-series (1982-2001) for 17 species caught during trawl surveys off Mauritania, with the NAO index, an upwelling index, sea surface temperature, and an index of fishing effort as explanatory variables. Both techniques gave coherent results, the most important common trend being a decrease in cpue during the latter half of the time-series, and the next important being an increase during the first half. A DFA model with SST and UPW as explanatory variables and two common trends gave good fits to most of the cpue time-series. (c) 2004 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.
- Analysis of size spectra off northwest Africa: a useful indicator in tropical areas?Publication . Stobberup, Kim A.; Inejih, C. A. O.; Traore, S.; Monteiro, C.; Amorim, Patrícia; Erzini, KarimChanges in the size spectra of demersal fish communities off Cape Verde (1988, 1994), Guinea (1985-1995), and Mauritania (1987-2001) were studied. Intercepts and slopes showed opposite trends for Guinea and Mauritania, but were relatively stable in spite of a strong increase in landings per unit area. For Cape Verde, there were marked changes in size structure, seemingly inconsistent with the more moderate fishing pressure there. Changes in size structure do not seem to be suitable indicators of the effects of fishing in areas characterized by faster growth rates, small sizes, high species diversity, and complex interrelationships, such as the tropics. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.
- Analysis of size spectra off northwest Africa: a useful indicator in tropical areas?Publication . Stobberup, K. A.; Inejih, C. A. O.; Traore, S.; Monteiro, C.; Amorim, P.; Erzini, KarimChanges in the size spectra of demersal fish communities off Cape Verde (1988, 1994), Guinea (1985-1995), and Mauritania (1987-2001) were studied. Intercepts and slopes showed opposite trends for Guinea and Mauritania, but were relatively stable in spite of a strong increase in landings per unit area. For Cape Verde, there were marked changes in size structure, seemingly inconsistent with the more moderate fishing pressure there. Changes in size structure do not seem to be suitable indicators of the effects of fishing in areas characterized by faster growth rates, small sizes, high species diversity, and complex interrelationships, such as the tropics. (c) 2005 International Council for the Exploration of the Sea. Published by Elsevier Ltd. All rights reserved.