Algal strains used in this experiment, along with their frequency in North American lakes.

1Obtained from the Carolina Biological Supply Company (North Carolina, USA). 2Isolated in the laboratory from local environmental samples. 3Obtained from the University of Texas Culture Collection (UTEX; Texas, USA). N/A: Genus not observed in the 2007 survey. Frequency (%): percentage of lakes in which this genus was present, based on a 2007 survey completed by the U.S. EPA (n = 1154 lakes) [13]. Rank Freq: of the 262 total genera found, ranking based on how frequently the particular genus was observed. Rank Abundance: ranking based on the average abundance of genera in all lakes where present.