In 1864, Tasmania introduced brown trout from England for sport; 162 years later, conservationists are creating trout-free havens for a native fish with only about 6,000 left

• The Swan galaxias (Galaxias fontanus), a small, scaleless freshwater fish found only in eastern Tasmania, has been reduced to an estimated 6,000 individuals.
• According to ABC News, the species now survives mainly in small, isolated headwater streams where natural barriers such as waterfalls stop predatory trout