Proportion of successfully fertilized eggs in brackish water vendace (A) (%, n = 51–104 eggs per treatment), brackish water whitefish (B) (%, n = 51–104 eggs per treatment), anadromous sea-migratory whitefish (C) (%, n = 50–51 eggs per treatment), freshwater vendace (D) (%, n = 55–80 eggs) and freshwater whitefish (E) (%, n = 55–80 eggs). Experiments done in different sulfate (SO₄^2–) treatments and in control treatments (BW = brackish water, RW = R. Kokemäenjoki water, LW = L. Konnevesi water) with background sulfate concentrations. The significance levels are above the bars (Kruskall-Wallis): − = P > 0.05, * = P < 0.05, ** = P < 0.01. Vertical lines on bars represent the 95% confidence limits.