Physicochemical and biological variables measured in 110 national monitoring lakes between 1992 and 2022.

Phytoplankton metrics (n=5): number of taxa, taxon biovolumes, diversity (Hills N2), % cyanobacteria and between-year Euclidean distance*. 5. Littoral taxon abundances (numbers per unit effort) for samples collected in October/November (n=681 taxa). Abundances were Hellinger transformed. 6.

Littoral metrics (n=4): number of taxa, total abundance, diversity (N2) and between-year Euclidean distance 7. Profundal taxa abundances (individual per m2) for samples collected in October/November (n=321 taxa). Abundances were Hellinger transformed. 8.

Profundal metrics (n=4): number of taxa, total abundance, diversity (N2) and between-year Euclidean distance.

• Between-year Euclidean distances were calculated using detrended correspondence analysis axes 1-3 as as d=√((x2 – x1)² + (y2 – y1)²) + (z2 – z1)²), where x1, y1, z1 represent DC axis scores one, two and three, respectively, at any year and x2, y2, z2 represent DC axis scores one, two and three, respectively, for the previous year.