The On the Fly Festival mixed a celebration of fly fishing, the Mataura River and education, as the Environment Southland team allowed people to have a fish while learning about the native fish and microbiome. Pictured: Environment Southland biosecurity plant leader Jolie Hazley, Shiloh Johnstone, 1, Bethany Johnstone, 4, and Peter Johnstone. PHOTOS: GERRIT DOPPENBERG. The On the Fly Festival in Gore reeled in a thousand people yesterday afternoon to celebrate the Mataura River, from its microbiome all way to the catch.