Population fluctuations of small pelagic fishes (SPF) around Japan were briefly reviewed for Japanese sardine,Japanese anchovy,chub mackerel,Pacific saury,Japanese jack mackerel,and Japanese common squid. The catch and biomass of SPF generally showed decadal-scale variability with prominent species replacements since the 1900s. The causes of species replacements were generally associated with climatic/oceanic variability,particularly regime shifts. Although overcapitalization of purse seine fleets during the 1980s prevented the recovery of Pacific stocks of sardine and chub mackerel during the 1990s,they have been recovering since the mid-2000s owing to strong year classes and reduced exploitation rates. The fundamental cause of overfishing was a mismatch between investments in purse seine fleets during the 1980s and poor ocean productivity since the 1988/89 regime shift,when dominant SPF began to shift from sardine to anchovy. Basic ideas for fisheries management of SPF around Japan were proposed,considering climate change,naturally and drastically changing SPF populations,and socio-economic factors,which would benefit fishers.
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