The first concerned the benthic population originating from the bloom of 2005, which was sampled in November 2005. The first 2 cm of the surface layers of each core, containning benthic Microcystis, was pooled and homogenized before distributing into glass containers. Fifteen milliliters of this homogenized sediment was placed in 40 mL glass containers, and 20 mL of filtered lake water was added. These experimental devices were exposed in triplicate to three different temperature, with or without light, and with or without mechanical mixing of the sediment .