Experimental approach
Temperature, initial phosphorus concentration and PAR were tested to determine their influence on microalgae growth rates and phosphorus uptake. A summary of the levels used for each factor is shown in Table 2. PAR and temperature levels were representative of cold region summers when WSPs are ice free and biological activity may occur. PAR levels were based on monitoring conducted from 2011 to 2014 at WSPs located in Pond Inlet (72°41′57″N, 77°57′33″W) and Kugaaruk (68°31′59″N, 89°49′36″W), Nunavut, Canada (unpublished). Temperature values were based on typical maximum (∼15 °C) and mean (10 °C) values found by Schmidt et al. (2016) in a study of four WSPs in Nunavut from 2011 to 2014. Schmidt et al. (2016) also reported lower temperatures (