Peru's Potato Guardians
As one of the world’s favourite vegetables, the potato has a global history spanning centuries and continents.
But modern agriculture and its reliance on monocultures is shrinking the genetic diversity of this important food staple, leaving it vulnerable to pests, disease and climate change.
Holding the world’s largest collection of potatoes in the world, the International Potato Centre in Lima, Peru is fighting back. As well as storing 7,000 potato samples in their gene bank, the organisation encourages locals to grow forgotten potato varieties in the Andes.
Russell Beard explores the genetic diversity of the potato and witnesses a local festival celebrating the humble tuber in the Sacred Valley of the Andes.
Oysters have an incredible ability to filter and remove pollutants from waterways, pumping water through their shells and taking out algae, sediment, bacteria and excess nitrogen as they feed.
Oyster reefs also provide a habitat for hundreds of species of plants and invertebrates, but despite enhancing the environment, 85 percent of oyster reefs have been lost worldwide.
Juliana Schatz travels to the east coast of the US to see how marine conservationists are trying to get these vital habitats flourishing again.
Dark Isle of Sark
Outdoor artificial lighting may be a fact of modern life, but it is costing the environment dearly.
Astronomers estimate that in the UK alone, wasted electricity from street lights emits carbon dioxide equivalent to an extra 160,000 cars on the road each year.
It is not just wasted electricity, artificially lighted night skies disrupt the natural cycles of plants and animals, changing habitats and ecosystems.
Residents on the Isle of Sark in the Channel Islands, however, are turning down artificial lighting as part of a scheme to reduce light pollution and return the island to its natural day-night cycle.
Chu Owen, an amateur astronomer, finds out how wildlife and communities are reaping the benefits of dark skies in the Isle of Sark - declared the world's first dark sky island.