Aquatic hyphomycete communities of 10 soft-water streams in Nova Scotia and New Brunswick were investigated with a foam sampling technique. The number of identifiable species varied between 26 and 42. Alkalinity, conductance, pH, and content of Ca2+, Mg2+, Na+, and K+ were measured in all streams. No significant correlation was found between number of fungal species and any of the chemical parameters. Combining the data with those of an earlier study revealed a significant, negative correlation between species number of a stream and its pH. The number of aquatic hyphomycetes appears to decline slowly, if at all, between 5 and 7. This is followed by a more rapid loss at values above 7.