Just throwing my two cents into this. I definitely agree that possibly from the recent earthquake, the creek area is warmer and the combination of hot springs runoff, and the seeps that come up through the creek bottom are warming the creek to higher temperatures than usual. There were areas along the creek where the sand felt hot even though the creek water felt cool. Coupled with the low creek levels and the sand bar slowing the flow, I
think the abundance of algae downstream is thermophilic green algae that is found in the hot spring pools and not the toxic cyanobacteria(blue-green algae) that occurs in polluted lakes(big bear) and rivers(from nitrogen rich agricultural runoff).
