SURVEY OF SWIMMING POOL ALGAE OF THE PHOENIX, ARIZONA, METROPOLITAN AREA1

Thirteen genera of algae were collected and identified from 110 swimming pools in the metropolitan area of Phoenix, Arizona. They included seven cyanophytes (Calothrix, Lyngbya, Oscillatoria, Nostoc, Phormidium, Plectonema, Pleurocapsa), four chlorophytes (Chlamydomonas, Diogenes, Oocystis, Roya), and two chrysophytes (Pleurochloris, Nitzschia). Pleurochloris pyrenoidosa Pascher was the most common swimming pool alga, occurring in 67% of the pools sampled. Species of Phormidium and Plectonema were the next most abundant, with species of Chlorophyta least common, occurring in less than 5% of the swimming pools surveyed. Algae occurred in swimming pools under a wide range of physicochemical conditions. A correlation between physicochemical parameters monitored and the appearance of a particular algal species was not evident.