Dr Helen Scales is a marine biologist, writer and broadcaster. She is author of the Guardian bestseller Spirals in Time , New Scientist book of the year Eye of the Shoal , and the children's book The Great Barrier Reef . She writes for National Geographic Magazine, the Guardian, and New Scientist, among others. She teaches at Cambridge University and is science advisor for the marine conservation charity Sea Changers. Helen divides her time between Cambridge, England, and the wild Atlantic coast of France. Find Helen on Twitter @helenscales and Instagram @drhelenscales Marcel George is a London-based illustrator specializing in watercolour illustrations. He has produced work for clients such as the Financial Times, Esquire and the Wellcome Trust.