A new series of the topical science programme. Geoff Watts investigates the crisis hitting the nation's favourite fish. Cod stocks have dwindled to dangerously low numbers, but is it simply due to over fishing? New research suggests that a tiny creature no bigger than a grain of rice may hold the key to the cod's survival. In a race against time, scientists are launching their bid to save the fish from extinction. Plus a review of the week's top science stories. Producer Alexandra Feachem EMAIL: radioscience@bbc.co.uk