Global fish consumption is at an all-time high; we eat an average of 17 kgs of seafood in a year. In fact, more than a billion people rely on the ocean for their primary source of food. But if fishing continues on the course it's on, in less than one hundred years more than half of the marine species may be on the brink of extinction. A major cause is overfishing; when so many fish are caught the population can't replace enough to reproduce, leading to depletion or total extinction of species. Apart from the food we eat, unsustainable fishing also has a larger impact on marine ecosystems and economic development. Today only 3% of the world's oceans are legally protected. On the next Stream we discuss overfishing and the impact it's having on the oceans and economies of the world. Join the conversation at 1930GMT.