Harp Lake is intensively monitored by the Dorset Environmental Science Centre, Ontario. Harp is an oligotrophic lake with a surface area of 0.714 km2 and a watershed area of 4.7 km2. Each of the six streams as well as the lake’s outflow is monitored for discharge flow rates and sampled fortnightly for water chemistry. The lake is also sampled for chemistry as well as phytoplankton and zooplankton at the same frequency. THELMA (The Harp Environmental Lake Monitoring Ark) has monitored meteorology and a suite of physical and biological parameters every 10 minutes since the summer of 2010 with the support of the Harp Lake Association.