Infinite Oceans

Our oceans seem so vast, it's hard to imagine them ever running out. We say there's always another fish in the sea, and when we dump our waste, the solution to pollution is dilution. But can we really afford to treat them as infinite? With world population growing with year on year compound interest we'd better think again. And... did you know you're wearing a space suit? Professor Richard Kenchington is from the National Centre for Ocean Resources and Security. Interview by Tom & Rod