This week Ed Balls, Ade Adepitan and Cherry Healey look at seafood - a commodity the UK buys and sells in huge quantities. Surprisingly, the fish caught off British shores is largely dispatched abroad as exports, whereas the fish we eat here tends to be imported.

Ed is at Heathrow Airport, a crucial link in Britain's seafood supply chain. As a cargo hub, Heathrow handles a third of the UK's long-haul export goods, by value. And sending out seafood by air is a huge part of Heathrow's daily operation. Ed sees how crates of seafood are transported beneath the feet of long-haul passengers, in cargo holds, and how this dual purposing of flights allows the Scottish salmon industry to export nearly a quarter of a billion pounds worth of salmon a year to far flung places like the USA and China. Ed also goes behind the scenes of the airport operations centre to witness how delays can affect Britain’s seafood supply chain.

Cherry is in the Scottish Highlands to uncover why the world is so fond of salmon farmed in its beautiful landscape. She travels to Inveraray on the shores of Loch Fyne to fish for Langoustine. It is our second biggest seafood export and is often served breaded and deep fried under its other name - scampi.

And Ade travels to Iceland to catch one of Britain’s favourite fish - cod. Due to its popularity, the UK imports over 100,000 tonnes of cod a year. He unravels the story of one of the most unusual trade conflicts in history - the Cod Wars. Show less