Fancy this for lunch: sea cucumber tea? Wolffish and chips? Trout candy floss and chocolate starfish? Heston turns to the sea in this special episode of Feast.

Across the world's seas, fish stocks are dwindling. If current trends continue, many will collapse completely in the next 50 years. But to super chef Heston Blumenthal this isn't the time for doom and gloom - this is the culinary opportunity of a lifetime. He is certain the sea is full of delicious, unused alternatives to our traditional fish suppers.

Heston dives straight in at the deep end as he creates an amazing sustainable seafood menu. He takes a trip to the fjords of Iceland to catch a dangerous fish the Vikings loved, goes diving for sea cucumbers in Scotland, and turns trout and crab into a delicious dessert.

As his starter for the feast Heston conjures up a Fishy Afternoon Tea complete with a side of Laughing Gas.

The magnificent main course is Heston's Day Out at the Seaside with Wolffish Cheeks and Saucy Seagull.

And to round off the feast it's time for Heston's guests to venture to the tropical deep for an Edible Coral Reef complete with Chocolate Starfish.

Heston's celebrity guests are Jonathan Ross, comic actress and impressionist Ronnie Ancona, actress Morwenna Banks, TV adventurer Ray Mears, actor Denis Lawson, and ex Blue Peter presenter Zoe Salmon.