Cod Love: The secret sounds of the seas
Audiences have been captivated by the stunning visuals of the BBC's Blue Planet II over the past few weeks - but one of the greatest technological advances in this series has been the way engineers have been able to capture the sounds of the ocean.
In this extended interview, Professor of Marine Biology and sound recordist Steve Simpson tells Mark Mardell on Radio 4's The World This Weekend about his own secrets of the deep - and we hear from his favourite fish.
(Photo: A giant cuttlefish displaying mating aggregation in South Australia. Credit: Hugh Miller / BBC Pictures)