Fig. 3

ANCOVA results for BLM vs. test results: Lines fitted by ANCOVA. The lines depict the relationship for the ratio between measured and BLM calculated toxicity (measured LC₅₀, EC₅₀) as well as the ratio between the molar sum of metals (Fe, Al) and DOC in four lakes. Red line ratio of LC50’s for D. magna; blue line ratio between NOEC and EC50 for P. subcapitata. The greyed-out symbols indicate LC-ratios for D. pulex that was exposed only to water from two lakes. D. pulex data was not part of the ANCOVA. The effect (slope) is statistically significant but the slopes does not significantly differ between the two species (Table 3)