Dougie is in Ullapool, where he joins a wildlife-watching sea tour to find out about the growing problem of disturbances to marine wildlife. Incidents of scaring seals, dolphins and porpoises with power boats and kayaks have been reported, and he meets the local children who are campaigning to raise awareness. Christina takes a dip in the River Larig, near Lochearnhead, to search for invertebrates, and she finds out why conservationists are planting dead tree roots into the river bank. JJ tries tree coring and learns what the rings in a tree trunk can tell us about climate change. And Hayden Lorimer reveals the double life of landscape photographer Walter Poucher.