"It is hard to estimate the devastating effect of trawling on marine life," says one Esperanza crew member. Another laments the current state of affairs: "Despite what governments say and what the big fishing companies say it is getting less all the time, less and less fish." And what happens if there is less fish? His answer is grim: "The ocean dies...basically."

Off the coast of Guinea the crew spot what they suspect to be an unlicensed ship, trawling illegally and breaking regulations. We witness the Esperanza chase down the pirate ship, Binar 4, and trail it from the Guinea coast to the Canary Islands and on to its final destination: Las Palmas. The crew fears that on their arrival in the port, the pirates may be able to evade officials by using EU stamped boxes and presenting what is allegedly a license from the Spanish government. Will the crew be able to convince the authorities of the ship's illegality before it is too late?

A shocking fact to emerge from this saga is that illegally sourced fish is finding its way into Europe through official channels, and so onto our dinner tables. This is a documentary with a powerful message. Few are aware that by 2050 we could be faced with extinct fish stocks unless rigorous sustainability measures are put in place. What can we do about it? "Think about what we are putting in our mouths," is one Greenpeace official's suggestion. And after watching this documentary, it would be hard not to do just that.