High salt tolerance but no local adaption to road salts in Tetrahymena ciliates

Road salt application improves road safety but leads to salinization of nearby freshwater ecosystems. If populations readily adapt to their local salinity environment, then we expect to find differences in salt tolerance between populations found near vs. far from roads. We determined the salt tolerance of 10 wild strains of the freshwater microbial eukaryote <i>Tetrahymena</i> . We found no significant correlation between salt tolerance and road distance, suggesting that these populations are not locally adapted to their salinity environment. This result may be due to the unexpectedly high salt tolerance across lines, unknown patterns of migration between ponds, or sampling conditions.