Until recent decades, most people considered the oceans to be an inexhaustible resource so vast and so plentiful that it was beyond humanity's ability to deplete it of fish or seriously pollute its waters. Today we know that is far from the truth.

Since the mid-20th century, advances in technology have given rise to massive industrial fishing operations that can rapidly empty waters of species like bluefin tuna or Atlantic cod while satisfying an ever-increasing demand for seafood. UN-tracked fisheries have shown steady declines in catches since 1988—even as more fishers take to the water with ever more efficient gear. Some studies estimate that populations of large ocean fish are only 10 percent as big as their preindustrial levels.

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