Fairweather T. P. auteur aut IRD van der Lingen C. D. auteur aut IRD Booth A. J. auteur aut IRD Drapeau Laurent auteur aut IRD van der Westhuizen J. J. auteur aut IRD text journalArticle eng Six indicators were investigated for South African sardine Sardinops sagax and anchovy Engraulis encrasicolus: mean length of catch, length-at-50% maturity, total mortality, exploitation rate, ratio of bycatch, and centre of gravity of commercial catches. Sardine length-at-50% maturity is the most promising as a descriptive indicator because it is positively correlated with population size for an extensive time period (1953-2005). The remaining indicators were limited by shorter data-series (1984-2005). However, mean length of catch, ratio of bycatch and exploitation rate were found to be useful when considered in conjunction with other indicators. The centre of gravity of commercial sardine catches has shown a significant eastward shift from the West Coast, whereas that of anchovy has remained off that coast. Ratio of bycatch indicates that school composition is a reliable descriptive indicator of relative abundance in the two species. Fewer indicators for anchovy were useful, which is attributed to this species' flexible life-history pattern. specialized anchovy biological indicator exploitation maturity pelagic sardine 036 040 28 3-4 661-680 2006 1814-232X https://www.documentation.ird.fr/hor/PAR00001370 1814-232X https://www.documentation.ird.fr/hor/PAR00001370 IRD - Base Horizon / Pleins textes 2007-03-01 2017-08-23 PAR00001370 fre