Sardine populations in western and eastern boundary current systems respond oppositely to decadal-scale ocean temperature anomalies. Using otolith microstructure and stable isotope analyses, this study reveals that habitat temperature, early life growth rates, energy expenditure, metabolically optimal temperature, and the growth-temperature relationship differ significantly between western (Japan) and eastern (California) North Pacific sardine subpopulations. These differences in life-history traits, also observed in South African sardine subpopulations, contribute to their contrasting responses to climate change.

Tatsuya Sakamoto, Motomitsu Takahashi, Ming-Tsung Chung, Ryan R. Rykaczewski, Kosei Komatsu, Kotaro Shirai, Toyoho Ishimura, Tomihiko Higuchi