Data for Contrasting life-history responses to climate variability in eastern and western North Pacific sardine populations

Massive populations of sardines inhabit both the western and eastern
boundaries of the world’s subtropical ocean basins, supporting both
commercial fisheries and populations of marine predators. Sardine
populations in western and eastern boundary current systems have responded
oppositely to decadal scale anomalies in ocean temperature, but the
mechanism for differing variability has remained unclear. Here, based on
otolith microstructure and high-resolution stable isotope analyses, we
show that habitat temperature, early life growth rates, energy
expenditure, metabolically optimal temperature and, most importantly, the
relationship between growth rate and temperature were remarkably different
between the two subpopulations in the western and eastern North Pacific.
Varying metabolic response to environmental changes partly explain the
contrasting growth responses. Consistent differences in the life-history
traits are observed between subpopulations in the western and eastern
boundary current systems around South Africa. These growth and survival
characteristics can facilitate the contrasting responses of sardine
populations to climate change.