It's difficult to imagine the sea ever running out of fish.It's so vast, so deep, so mysterious.Unfortunately, it's not bottomless.(1)_______________________.Destroy the fish,and you destroy the fishermen's means of living.At least 60 percent of the world's commercially important fish species are already over-fished, or fished to the limit.(2)_______________________.Big, high-tech fleets ensure that everything in their path is pulled out of water.Anything too small, or the wrong thing,is thrown back either dead or dying.That's an average of more than 20 million metric tons every year.When you consider that equals a quarter of the world catch,you begin to see the size of the problem.In some parts of the world,for every kilogram of prawns caught,up to 15 kilograms of unsuspecting fish and other marine wildlife die,simply for being in the wrong place at the wrong time.True, some countries are beginning to deal with this problem,but it's vital we find rational ways of fishing before every ocean becomes a dead sea.(3)_______________________.