Imagine what people would say if a band of hunters strung a mile of net between two immense all-terrain vehicles and dragged it at speed across the plains of Africa. This fantastical assemblage, like something from a Mad Max movie, would scoop up everything in its way: predators, such a lions and cheetahs, lumbering endangered herbivores, such as rhinos and elephants, herds of impala and wildebeest, family groups or warthog and wild dog. Pregnant females would be swept up and carried along, with only the smallest juveniles able to wriggle through the mesh.

Picture how the net is constructed, with a huge metal roller attached to the leading edge. This rolling beam smashes and flattens obstructions, flushing creatures into the approaching net. The effect of dragging a huge iron bar across the savannah is to break off every outcrop, uproot every tree, bush and flowering plant, stirring columns of birds into the air. Left behind is a strangely bedraggled landscape resembling a harrowed field. The industrial hunter-gatherers now stop to examine the tangled mess of writhing or dead creatures behind them. there are no markets for about a third of the animals they have caught because they don’t taste too good, or because they are simply too small or too squashed. This pile of corpses is dumped on the plain to be consumed by carrion.

This efficient but highly unselective way of killing animals is known as trawling. While it is not practiced on the African savannah, fortunately, it is practiced the world over every day, in all seas and oceans. A lot of our seafood and seafood products come to us in this way. While we talk about the proverbial ‘price of fish’, the cost is much higher when we also consider the environment. Our love affair with fish and seafood is absolutely unsustainable.

By Charles Clover, from The End of the Line (book & documentary)