Tuesday, April 26, 2005

Shifting Baselines

I first heard the term “shifting baselines” in January, at a dinner party with a neighbor, Kent Redford, who is a conservation biologist with the Wildlife Conservation Society. As with many terms, once you hear it for the first time, it pops up again and again. David Conover, of Stony Brook University’s Marine Science Research Center, used it a couple of weeks ago at a conference in the city. And I came upon it again this morning, in the Times, in a profile of Jeremy Jackson, of the Scripps Institution of Oceanography. The Times reported:

He helped create a Web site, shiftingbaselines.org, to point out that the changes people saw in their 20th-century lifetimes were just small snapshots in a larger picture of environmental decline that has been accelerating for 200 years.

At shiftingbaselines.org, there is an offer – a command, almost – to take material from the website and use it for a good cause. I read a piece by Randy Olson, of USC, that defines “shifting baselines” and explains its relevance to marine ecosystems and elsewhere:

There is a new term in the environmental movement. …

The term is "shifting baselines," and you do need to know it, because shifting baselines affect the quality-of-life decisions you face daily. Shifting baselines are the chronic, slow, hard-to-notice changes in things, from the disappearance of birds and frogs in the countryside to the increased drive time from L.A. to San Diego….

The term was coined by fisheries biologist Daniel Pauly in 1995….

Among environmentalists, a baseline is an important reference point for measuring the health of ecosystems. It provides information against which to evaluate change. It's how things used to be. It is the tall grass prairies filled with buffalo, the swamps of Florida teeming with bird life and the rivers of the Northwest packed with salmon. In an ideal world, the baseline for any given habitat would be what was there before humans had much impact.

If we know the baseline for a degraded ecosystem, we can work to restore it. But if the baseline shifted before we really had a chance to chart it, then we can end up accepting a degraded state as normal -- or even as an improvement.

These questions are particularly important to ask about oceans, my main research interest. Last year Jeremy Jackson of the Scripps Institution of Oceanography brought the problem into focus with a cover article in Science that was chosen by Discover magazine as the most important discovery of the year.

Jackson and his 18 co-authors pulled together data from around the world to make the case that overfishing had been the most important alteration to the oceans over the past millennium. Furthermore, humans have had such a strong effect on the oceans for so long that, in many locations, it is difficult to even imagine how full of life the oceans used to be.

One of scientists' biggest concerns is that the baselines have shifted for many ocean ecosystems. What this means is that people are now visiting degraded coastal environments and calling them beautiful, unaware of how they used to look.

One of the things I tried to do in my Long Island Sound book was present a portrait of what the natural world was like 400 years ago, and when I give a talk I make sure to include a section that sketches the same thing – the incredible spring spawning runs of anadromous fish, the huge sturgeon, the lobsters big enough to feed 12 men. (I understand John Waldman did the same thing for New York Harbor in his book Heartbeats in the Muck, although I haven’t read it yet.)

For Long Island Sound, this is the baseline. We shouldn’t be satisfied merely to make things better compared to 1987 or some other year when conditions were appalling. Bring back the lobster, bring back the winter flounder. Let the shad spawn in dozens of rivers.

Kent Redford, by the way, turned out to be an excellent cook. He served striped bass brightened by a tiny branch of tart, scarlet currents. Were there any fish he wouldn’t serve? Absolutely, he said. Chilean sea bass. They’ve been so overfished it would unconscionable to eat one.


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