Figure 1.
Time series (1964–2009) of oxygen and fish.
Temporal variations of DO in mL L−1 (black dotted line) (A), DOsat in % (black dashed line) (B), Z2 mL/L, in m (black solid line). Black solid line show the smoothed time series; gray solid line show the 4-years moving average. C. anchovy catches (blue solid line), biomass by VPA (blue dashed line) and acoustic biomass (blue dotted line). D. Temporal variations of sardine catches (red solid line), biomass by VPA (red dashed line) and acoustic biomass (red dotted line).
Figure 2.
Time-lagged cross correlations of oxygen and fish.
Time-lagged cross-correlations in year between smoothed times series of anchovy and sardine catches and biomass by VPA and acoustic biomass and DO, DOsat and Z2 mL/L. Values above (below, respectively) the top (bottom) dotted lines are significant at p = 0.001.
Figure 3.
Cross-shore profiles of oxygen and fish biomass.
A. Mean cross-shore profiles of DO in mL L−1 (black dotted line), DOsat in % (grey dashed line), Z2mL/L in m (black solid line), and the acoustic-estimated biomass of anchovy (blue solid line) and sardine (red solid line). B. Decadal evolution, from the 1960s to the 2000s, of the distance from the coast of the DO, DOsat and Z2mL/L isovalues equal to 4.4 mL L−1, 80% and 40 m, respectively.
Figure 4.
Cubic spline smoother fits (black solid lines) of GAMs (colored areas show 95% confidence limits) of anchovy (blue areas) and sardine (red areas) acoustic local biomass according to A. DO in mL L−1, B. DOsat in % and C. Z2 mL/L in m. The y-axes are relative and correspond to the spline smoother that was fitted to the data such that a y-value of zero is the mean effect of the variables on the response. Right y-axis corresponds to sardine in A.
Figure 5.
Conceptual model of decadal changes in anchovy and sardine populations in the southeastern tropical Pacific.
A. Schematic of the temporal evolution of large plankton and anchovy (blue solid line), and oxygen, small plankton and sardine (red solid line) between 1960 and 2010. B. Energetic costs of feeding on dominant plankton size-spectra for anchovy and sardine according to the scenarios from A. C. Schematic of the available habitat for anchovy (blue shaded area) and sardine (red shaded area).