By documenting this history, Holy makes it clear that our ideas about healthy fish populations and healthy oceans may in fact be incorrect inasmuch as the oceans of a century or two ago were not as pristine as we imagine. The story of the North Atlantic is one of making the same mistakes over and over again. Under such circumstances, how could anyone determine what marine life in the North Atlantic should look like? Some people may wonder why it matters. After all, we could simply, in the North Atlantic and elsewhere, change the management practices to suit the current ecosystem. But the question would remain if that would produce the most resilient and abundant fish populations. Holy notes many historical descriptions of areas almost choked with fish. Can we ever recreate those conditions? Deserted Ocean doesn't try to answer such a complicated question, but it does provide a clear picture of what we've lost through greed.
Holy also surveys the history of cod fishing and whaling, two egregious examples of humanity's capacity to devastate a natural resource. Cod especially illustrates how important it is to adopt a precautionary approach to fishing. It took centuries to overfish cod near Newfoundland, and though the fishery finally closed completely to fishing years ago, the population has not rebounded. Signs of danger were ignored for years because fishery restrictions are politically unpopular. We don't need to keep making the mistakes of the past. Deserted Ocean demonstrates that overfishing isn't the creation of hysterical fish-huggers. It's a real phenomenon, and the sooner we realize that the better.