POSSIBLE MECHANISMS UNDERLYING FLUCTUATIONS IN THE FAR-EASTERN SARDINE POPULATION INFERRED FROM TIME-SERIES OF 2 BIOLOGICAL TRAITS

A cycle of fluctuation in the Far Eastern sardine, Sardinops sagax, population is accompanied by an abrupt drop and recovery of fish size and lipid content of parent fish, which may reflect a phase variation from coastal to oceanic and its reverse. The cycle begins with die survival success of a smaller number of eggs produced by high-quality parents, which is triggered by a global climate change (density independent process), and finally ends in the survival failure resulting from an overexpansion of an enormous number of fish produced by low-quality parents (density-dependent process).