Shifting Baselines

The book The Unnatural History of the Sea by Callum Roberts, a marine ecologist at the University of York in England, is the 2007 shifting baseline story of the year. Roberts pulls together the best historical studies of fisheries, photos, and woebegone descriptions of former marine abundance. A whole chapter is dedicated to the shifting baselines concept but the entire book echoes the syndrome (read more at the book's website). Included are accounts of a 24-square foot halibut, the great profusion of sharks in the eastern Pacific, and why the year 1900 is a bad baseline for the North Sea. Roberts describes how cod off the Nova Scotian shelf are now one-third of one percent of 1850s levels.

The Unnatural History of the Sea compiles the most recent research of top marine scientists, including Jeremy Jackson and Daniel Pauly, into a succinct eulogy for our seas. But Roberts believes that, unlike doctors, we don't have to bury our mistakes. We can learn from our errors and implement reforms.

From the Preface:

In my work as a scientist, I find that few people really appreciate how far the oceans have been altered from their pre-exploitation state, even among professionals like fishery biologists or conservationists. A collective amnesia surrounds changes that happened more than a few decades ago, as hardly anyone reads old books or reports. People also place most trust in what they have seen for themselves, which often leads them to dismiss as far-fetched tales of giant fish or seas bursting with life from the distant, or even the recent past. The worst part of these 'shifting environmental baselines' is that we come to accept the degraded condition of the sea as normal. Those charged with looking after the oceans set themselves unambitious management targets that simply attempt to arrest declines, rather than rebuild to the richer and more productive states that existed in the past. If we are to break out of this spiral of diminishing returns and diminished expectations of the sea, then it is vital that we gain a clearer picture of how things have changed and what has been lost.