We asked Sir David Attenborough and four other leading thinkers on ocean conservation how they would invest $1bn to protect the ocean. Some of their answers may surprise you. Film supported by @blancpain https://www.woi.economist.com/ Click here to subscribe to The Economist on YouTube: https://econ.st/2xvTKdy For more from Economist Films visit: http://films.economist.com/ Check out The Economist’s full video catalogue: http://econ.st/20IehQk Like The Economist on Facebook: https://www.facebook.com/TheEconomist/ Follow The Economist on Twitter: https://twitter.com/theeconomist Follow us on Instagram: https://www.instagram.com/theeconomist/ Follow us on Medium: https://medium.com/@the_economist