Slow-Motion Disaster Below the Waves
There is a new term in the environmental movement. It sounds esoteric, like the kind of thing you don't really need to understand, something you can leave to the more technical types.
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. If your ideal weight used to be 150 pounds and now it's 160, your baseline -- as well as your waistline -- has shifted.
The term was coined by fisheries biologist Daniel Pauly in 1995. It was a term we'd apparently been needing, because it quickly spread to a variety of disciplines. It's been applied to analysis of everything from deteriorating cities to declining quality of entertainment.
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.
The number of salmon in the Pacific Northwest's Columbia River today is twice what it was in the 1930s. That sounds great -- if the 1930s are your baseline. But salmon in the Columbia River in the 1930s were only 10% of what they were in the 1800s. The 1930s numbers reflect a baseline that had already shifted.
This is what most environmental groups are now struggling with. They are trying to decide: What do we want nature to look like in the future? And more important: What did nature look like in the past?
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.
