Environmental indicator values for select algae taxa in the Great Lakes.

Select algae taxa in the Great Lakes and their environmental indicator values based on biovolume distributions across the environmental gradients. Negative (−) and positive (+) signs indicate significant linear relationships (P<0.05) based on the Pearson product moment correlation. Gaussian optima (Gau) display an asterisk (*) if fitted residuals were significantly smaller (t-test; P<0.05) than residuals from the linear fit. WA indicates optima based on weighted-averaging. “Season” and “Lake” coefficients reflect seasonal and spatial occurrence of the taxa. Indicator values from 0 through 10 respectively represent whether a given taxon had its greatest modeled abundance at a low or high region of a variable's gradient. Indicator numbers for seasons or lakes represent the relative proportion that each taxon achieved in 2007–2011, again scaled from 0 to 10.