Surface-sediment cores were taken on February 21(2005) at 30 locations across
the bottom of the lake (Fig. 2) using a mini-Glew gravity corer. The top 1-cm of each
core was used for analysis. Samples of algae growing on rocks immediately around the
shoreline were sampled by boat on February 23, 2005, using a toothbrush at 21 locations
around the shoreline (Fig. 2). Breifly, rocks were scraped with a toothbrush for a periods
of 5 seconds and sample was rinced off the toothbrush into a vial with water. All samples
were preserved with ethanol.