Rupert Murray's new documentary "The End of the Line," based on the book of the same name by British journalist Charles Clover, presents a timely and shocking (but maybe not too surprising) look at the devastating overfishing of our oceans that has occurred over the last century. Through interviews with leading ocean scientists, local fishermen and concerned journalists from Asia to Africa to Alaska, the film explains how the majority of the world's edible fish will go extinct by 2048 if we do not change the way we fish.

Evidently, the world's fish stocks have been steadily declining for the last 20 years, even as more and more boats are sent out each year. Nowhere is this more evident than in the North Atlantic, where cod once filled the waters off Newfoundland. Today, a moratorium placed on cod fishermen there in the early 90s has not yet been lifted-overfishing was so rampant that the fish were brought to the brink of extinction, and even without human interference they have had an extremely hard time repopulating over almost two decades. And pretty much any big ocean fish you can think of is either in a similar situation or well on its way.

The film details how practices such as "bottom trawling" and long-line fishing catch and kill countless numbers of undesired fish and sea plants, which are simply thrown back into the ocean while the few desired fish are kept for consumption. These methods are something akin to fishing with dynamite, and the violence with which they disrupt the natural habitats of millions of aquatic organisms is astounding.

The business of fishing, which is seen through the eyes of a small-time fisherman in Senegal, a former tuna hunter turned conservationist from the Mediterranean, and many others, is exposed as fantastically wasteful and destructive, and with rare exception driven by nothing but profit. And given that the industry's source is vast, distant from its consumers, and essentially invisible, this kind of makes sense. Except that if the industry keeps doing what it's doing, it will pretty soon no longer have any fish to catch.

The problem is, of course, not just limited to the big fish. The incredible value of bluefin tuna, for instance, makes its near extinction among the most noteworthy. But equally damaging is the effect that this depletion has on the other sea creatures that live with the big fish we hunt. Increases in diseased lobster in Maine, rays in Maryland, and jellyfish everywhere can be attributed to the reduction in populations of larger fish that prey on them. Ecosystem disruption, even more invisible to the human eye than fish stock depletion, may present an even greater threat in the long run.

America actually seems to be leading the way somewhat on enacting some of the protective measures, such as strict catch quotas and the creation of ocean preserves, that can combat this problem. Fishermen seem to be catching on to the fact that if they don't work within reasonable restrictions, they will all be out of work in the next 40 years. But, according to the film, only .6% of the ocean is currently protected, and the sort of fishing quotas that rule many of our coasts are either not in place in much of the rest of the world, or simply ignored. And we live in a country that both embraces food fads such as the recent fascination with omega-3 fatty acids, and has some serious restraint problems. So really, it seems that reversing this devastation is going to be quite difficult.

There are, however, many efforts being made to help consumers make smart decisions when they buy fish. Mark Bittman has written extensively on the subject, and some stores like Whole Foods are beginning to stock more sustainable fish. Many restaurants are being more careful about their fish sources, and often will inform diners where fish come from on the menu (or, in the case of Nobu, that it is endangered).  Even though a change in personal behavior will take a long time to translate into the end of large-fleet overfishing, it is still the easiest and surest step we can take in helping to preserve our oceans. Everything from eating less fish, to eating sustainably caught fish, to eating smaller fish can help minimize the damage and start our oceans on the path to recovery.