Max Pearson presents a compilation of this week's Witness History programmes from the BBC World Service.
You'll hear the story of how a marine biologist made a shocking discovery finding small bits of plastics floating thousands of miles of the east coast of America.
Then, marine biologist Christine Figgener talks about the history of oceans.
Also, the world's first transatlantic concert, a dispute over sea cucumbers in the Galapagos Islands, the world's first tidal power station and the first woman to win a Olympic windsurfing gold medal.
(Photo: Garbage on beach. Credit: Getty Images)
Contributors: Edward Carpenter - Marine biologist John Liffen - Curator emeritus at the Science Museum in London Marcos Escaraby - Fisherman in the Galapagos Islands Alan Tye - Conservationist Marc Bonnel - Brittany historian Babara Kendall - Windsurfing champion