In the mid-1800s, Tasmanian sheep farmer James Youl embarked on a fanciful mission, to transport live Atlantic salmon eggs from the northern hemisphere to the south, thousands of miles across the seas, in the hopes of spawning a viable salmon colony in Australia. It was a mad endeavour that stretched the limits of science and technology, and defied the accepted laws of nature. 

• Guest: Steve Harris, author of Under the influence of salmon: how a man and a fish turned the world upside down
• Producer: Jack Schmidt