Fig. 2.

Dual relationship between zooplankton and hydrological factors in the 2 alternative configurations. (A) Relationships between the PC1 of hydrological factors (temperature and salinity 0–100 m in spring and summer) and PC1 of zooplankton parameters in the 2 configurations. Cod-dominated: r = 0.53, P = 0.03; sprat-dominated: r = 0.074, P = 0.81. Factor loadings show association of zooplankton PC1 with total zooplankton biomass, whereas PC1 of hydrology is related mostly to salinity in summer. Numbers associated with each point indicate observation year. (B) Density distribution of the correlation coefficients between the PC1 of hydrological factors and PC1 of zooplankton parameters, obtained by bootstrap resampling (10,000 times) in the whole study period and in the 2 configurations. See Table S4 for statistical comparisons among the distributions. In bold are the significant correlations, at α = 0.05.