New Zealand Tests Didymo-Killing Chemical

The first field tests of a chemical that could be used to kill didymo while not harming trout was conducted Tuesday in a branch of Princhester Stream, on the northern slopes of the South Island’s Takitimu Mountains. “On Tuesday, a helicopter had flown 831 litres of prepared Gemex to the release site, where it had been delivered into the water stream at a carefully gauged rate for an hour.” Didymo algae infestations have spread throughout South Island streams in recent years. Bruce Fraser in The Southland Times.