Climate, fishing, and fluctuations of sardine and anchovy in the California Current

TitleClimate, fishing, and fluctuations of sardine and anchovy in the California Current
Publication TypeJournal Article
Year of Publication2013
AuthorsLindegren M, Checkley DM, Rouyer T, MacCall AD, Stenseth NChr.
JournalProceedings of the National Academy of Sciences
Date Published2013/07

Since the days of Elton, population cycles have challenged ecologists and resource managers. Although the underlying mechanisms remain debated, theory holds that both density-dependent and density-independent processes shape the dynamics. One striking example is the large-scale fluctuations of sardine and anchovy observed across the major upwelling areas of the world. Despite a long history of research, the causes of these fluctuations remain unresolved and heavily debated, with significant implications for fisheries management. We here model the underlying causes of these fluctuations, using the California Current Ecosystem as a case study, and show that the dynamics, accurately reproduced since A.D. 1661 onward, are explained by interacting density-dependent processes (i.e., through species-specific life-history traits) and climate forcing. Furthermore, we demonstrate how fishing modifies the dynamics and show that the sardine collapse of the 1950s was largely unavoidable given poor recruitment conditions. Our approach provides unique insight into the origin of sardine‚Äďanchovy fluctuations and a knowledge base for sustainable fisheries management in the California Current Ecosystem and beyond.