It's Big Blue Week, and Hugh Fearnley-Whittingstall is celebrating the UK's extraordinary array of marine life. Hugh and the team focus on the UK's seashore. What secret sea life is waiting to be discovered on our island's edge? From seahorses to hermit crabs, otters to oysters, limpets to jellyfish - our shore is full of weird and wonderful creatures. Hugh looks back at film footage from his childhood, reawakening his passion for rock pooling. Wildlife cameraman Richard Taylor-Jones goes on the hunt for a marine monster - the barrel jellyfish. Lindsey Chapman heads to Lyme Bay, a Marine Protected Area, to explore how we can conserve our seabed and the marine life relying on it. Hugh relives a childhood passion as he rolls up his trousers to take us rock pooling. He discovers that some of the tiny creatures found on our beaches are, in fact, our sea's superheroes - raising the alarm to scientists investigating the gradual rise in temperature of our seas. We also link up with the Big Blue team in Monterey Bay, America, as they offer a ringside seat to one of the greatest animal gatherings on earth.