Helen Scales is a marine biologist, freelance researcher and broadcaster. She appears regularly on BBC Radio 4, Sky News and the BBC World Service, and has presented documentaries on topics such as whether people will ever live underwater, the science of making and surfing waves and the intricacies of sharks' minds.

Her doctorate involved searching for giant endangered fish in Borneo; she's also tagged sharks in California, and once spent a year cataloguing all the marine life she could find surrounding a hundred islands in the Andaman Sea. She is the author of a book about seahorses, Poseidon’s Steed, and her latest book is Spirals in Time: The Secret Life and Curious Afterlife of Seashells.