Abstract

<jats:p>
Sardines have been a major contributor to the pelagic fishery off southern
Africa for several decades. The South African and Namibian stocks are
separate, and seasonal hydrology, in conjunction with age-related behaviour,
produces the observed size-distribution patterns. Sardines are relatively
fast- growing and spawn repeatedly over the spring and summer months. Eggs and
larvae are transported from the Agulhas Bank to the west coast by the
north-flowing jet current at the shelf edge. Sardines are omnivorous,
microphagist filter-feeders and are important prey for many piscivorous
fishes, birds and mammals. There have been major fluctuations in sardine
population biomass in southern Africa which have been associated with
environment, regime shifts, recruitment and fishing. South African and
Namibian sardine catches peaked in the 1960s, declining dramatically
thereafter, and the pelagic fishing industry switched to anchovy. During the
1990s, sardine biomass increased but, although South African catches rose, the
Namibian stock collapsed again. The annual South African total allowable catch
is set through an operational management procedure that takes into account
biomass estimates from comprehensive hydroacoustic surveys and the sardine
by-catch in the anchovy fishery.</jats:p>