Relative abundances of the four major algal genera in BML surface waters: (A) Choricystis, (B) Cryptomonas, (C) Synechococcus, and (D) Euglena, based on 23S, 16S and/or 18S rRNA gene amplicon sequencing Also included for B) and D) are microscopic cell count data. Data points are means of three platforms ± 1 SEM. Where error bars are not seen they are contained within the symbol. The blue bar indicates alum addition. Dashed lines indicate running averages calculated based on sequential segments of the full dataset.