In this episode, we take measure of humanity's impact on the sea since we first settled along its coasts over 150,000 years ago. Human activity through history - first overfishing, then over-development of the world's coastlines, and the continuing pollution that we pour into the sea - have had unexpected consequences. But marine protected areas can have a huge impact on an ecosystem's ability to recover. Footprints in the Sand reveals the devastating impact of human activity on the ocean, focusing on the Mediterranean's contentious bluefin tuna fishery and the Gulf of Mexico's massive de-oxygenated dead zones. It also celebrates our successes with sustainable practices, like "no take" conservation projects managed by locals in Zanzibar, as well as the extraordinary turnaround in New Zealand's coral reefs.

Original broadcast on television as part of the series The nature of things. Teaching guide available under Additional Info tag. Also available as streaming on Curio.

Chaptered: Crisis beneath the waves Marine deserts Coastal zone ecosystems Restoring marine ecosystems.