Before Chris and Co get back for the start of the new series, Ben and Diana dive deep into the science of the sea. We find out why cold water corals can act as a climate calendar, how fish feminised by human female hormones have a surprising effect on the ecosystem and discover the marine micro-organisms that keep the climate in check. Also, why the humble garden pond can guard against global warming, and how penguins can be identified by their feathery fingerprint. Plus, in Kitchen Science, Ben and Dave have a unique tea party to find out if the saying 'as useless as a chocolate teapot' really holds (hot) water!