Annual treatments with barley straw are helping clean up Powderhorn Lake, a landlocked pond in south Minneapolis that's been plagued by the pea-soup hue of rampant algae growth.
The sunken mesh bags of straw were first installed near the shoreline in 2004 by the Minneapolis Park and Recreation Board. By 2006, light penetration had improved enough to allow aquatic plant growth, with at least two species returning by 2007.
The breakdown of the straw hinders algae growth, according to park officials, and the clearer water allows plants to grow. The return of plants means fewer nutrients will be available for algae.
Park officials have tried a number of water quality treatments at Powderhorn, and said that although it's hard to know which have had the most effect, the barley straw appears to represent a tipping point in the lake's improvement.
They say it avoids the use of algae-killing chemicals that poison fish and other aquatic life.
