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Shifting Baselines: Slow-Motion Disaster in the Sea

Randy Olson


“Shifting baselines” refers to the incremental lowering of standards, with respect to nature, in which each new generation:

  • lacks knowledge of how the environment used to be
  • redefines what is “natural,” according to personal experience
  • sets the stage for the next generation’s shifting baseline

December 2002

Shifting baselines result from chronic, slow, & hard-to-notice changes.

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.


It is difficult to imagine how full of life the oceans used to be. Photo: Olena Sullivan.

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 Los Angeles 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.

How baselines work in the environment

The term “shifting baseline” was coined in 1995 by fisheries biologist Daniel Pauly, University of British Columbia, Canada.3 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 the declining quality of entertainment.

Baselines document how things used to be and are used to evaluate change.

Among environmentalists, a baseline is an important reference point because:

  • It measures 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 bison, 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.

A baseline that shifted before it was charted can cause a degraded state to be accepted as normal.
Shifted baselines cause skewed statistics.

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. For example:4

  • 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 is your baseline.
  • But salmon in the Columbia River in the 1930s were only 10% of what they used to be in the 1800s. The 1930s numbers reflect a baseline that had already shifted.

That 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 importantly, what did nature look like in the past?

Shifting baselines in the oceans

How full of life were the oceans?
The damaging influence of overfishing had long ago shifted the baselines for ocean ecosystems.

The above 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.2

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 in the oceans over the past millennium
  • 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
A degraded kelp bed can look great to someone who is unaware of how much better it used to look.

One of the 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.

People go diving today in California kelp beds that are devoid of the large black sea bass, broomtailed groupers, and sheephead that used to fill them. And they surface with big smiles on their faces because it is still a visually stunning experience to dive in a kelp bed. But all the veterans can think is, “You should have seen it in the old days.”

Without the old-timers’ knowledge, it’s easy for each new generation to accept baselines that have shifted and make peace with empty kelp beds and coral reefs. Which is why it’s so important to document how things are — and how they used to be.

The future: oceans of jellyfish and bacteria?

An excess of jellyfish and bacteria signify a degraded ecosystem.

For the oceans, there is disagreement on what the future holds. Some marine biologists argue that, as the desirable species are stripped out, we will be left with the hardiest, most undesirable species — most likely jellyfish and bacteria, in effect the rats and roaches of the sea. They point to the world’s most degraded coastal ecosystems — places such as the Black Sea, the Caspian Sea, even parts of the Chesapeake Bay. That’s about all you find there: jellyfish and bacteria.

Jellyfish blooms are now a common occurrence.

We have already become comfortable with the new term, “jellyfish blooms,” which is used to describe sudden upticks in the number of jellyfish in an area. The phenomenon has become sufficiently common that an international symposium was held on the subject in 2000.5 Meanwhile, other types of world fisheries are in steep decline.

Once vibrant coral reefs in Jamaica are now mounds of dead corals covered by algae.

It is easy to miss changes in the oceans. It’s big and deep. But sometimes, if people have studied the same oceanic trends over time, we get a glimpse of a highly disturbing picture. The Scripps Institution’s Jackson, for example, has documented the nearly complete disappearance of the ecosystem on which he built his career — studying the coral reefs of Jamaica, about which he says:

Virtually nothing remains of the vibrant, diverse coral reef communities I helped describe in the 1970s. Between overfishing, coastal development, and coral bleaching, the ecosystem has been degraded into mounds of dead corals covered by algae in murky water.1

Nothing you would want to make into a postcard!

Public education about the problem

There are several efforts underway to raise attention to the problem:

Environmental groups are calling attention to the oceans’ problems.
They need mass support for saving the oceans.
  • Next year, two major reports will be released on the state of the oceans: the Oceans Report from the Pew Charitable Trusts, and the report of the U.S. Oceans Commission. The inside word is that they will conclude that the oceans are today in severe decline.
  • The Ocean Conservancy, Scripps Institution, and the Surfrider Foundation are mounting a major media for early next year to call attention to the overall fate of the oceans and the problem of shifting baselines.

The solutions are already known. We must

  • care more about the environment
  • work to prevent its decline

Hundreds of environmental groups have action plans to help achieve such goals. The only thing they are lacking is mass support.

Making the oceans healthy is everyone’s responsibility.

Reevaluating our personal baselines

The oceans are our collective responsibility. We all have to ask the questions:

Conclusion: We cannot afford to lower our standards for the environment.
  • What did they look like?
  • What are we putting into them?
  • Where did the fish we are eating come from?
  • Are my food preferences jeopardizing the health of the oceans?

And, in a more philosophical vein, we should consider the shifting baselines in our own lives, examining how and where have we lowered our standards to the point that we accept things that once would have been unacceptable. Our environment has clearly suffered from our increasing comfort with shifting baselines. I suspect our lives have suffered in other ways as well.

Randy Olson, Ph.D., is a marine biologist, science filmmaker, and lecturer at the University of Southern California. He received his Ph.D. in Biology from Harvard University in 1984. His specialty is the ecology of marine invertebrate larvae of such species as starfish, corals, and sea squirts. His film and video productions include a documentary on women scientists who work in deep-sea submersibles and the history of coastal overfishing.

Shifting Baselines: Slow-Motion Disaster in the Sea

BioScience Article

“Historical Impacts on River Fauna, Shifting Baselines, and Challenges for Restoration.”
The decimation of aquatic wildlife through overexploitation is usually perceived as a marine phenomenon, yet it has also been common in freshwater ecosystems. Paul Humphries? and Kirk O. Winemiller (BioScience, September 2009) argue that researchers have not thought about how the loss of these species has affected our current environment. Read the abstract, or log in to purchase the full article.

Rediagnosing the Oceans

This downloadable 7-minute film by Jeremy Jackson and Randy Olson conveys the message on the importance of history in diagnosing the problems of the oceans. Also, check out the downloadable film New England Kelp Beds.

Exploring the oceans

Click on “explore the oceans” section on the home page of the American Oceans Campaign for an interactive map, which will appear in a pop-up window. Highlight a body of water on the map to learn about it.

Scripps Institution of Oceanography

The institute’s mission is “to seek, teach, and communicate scientific understanding of the oceans, atmosphere, Earth, and other planets for the benefit of society and the environment.”

Surfrider Foundation USA

The foundation is a non-profit, membership organization “dedicated to protecting our oceans, waves and beaches.”

Oceans and Law of the Sea

Information on the three entities envisioned by the United Nations: International Seabed Authority, International Tribunal for the Law of the Sea, and the Commission on the Limits of the Continental Shelf.

What Does an Oceanographer Look Like?

Downloadable one-minute film from Randy Olson for Rutgers University’s Coastal Ocean Observation Laboratory. Requires Quick Time.

For students and teachers: ocean information

Quick facts, activities, and quizzes about the oceans, marine life, and how the U.S. Navy conducts marine research.

Randy Olson’s website where you can watch a flash slide show and learn more about the oceans and their depleting species.

Read a book

The Empty Ocean: Plundering the World’s Marine Life by Richard Ellis (Shearwater Books, July 2003). Ellis explains and details through both historical and scientific data the scope of the problem and offers some realistic alternatives to continued misuse and apathy.

Action alerts from Ocean Conservancy

Sign up to receive action alert emails to help the organization with its initiatives to maintain healthy oceans.

WWF campaigns

“Campaign for the environment no matter where you are in the world, all over the world.” This page is their “activist toolkit… tips for effective online activism.” Also, click on the map in the right menu bar to find a WWF campaign in your corner of the planet.

Protect coral reefs worldwide

ReefGuardian International asks you to “stand up for reefs” with their online petitions.

American Rivers campaigns

Learn about restoration of rivers in the U.S. and how you can help; see also their “take action center” for other opportunities.

Endangered Fish Alliance

The Toronto-based group of chefs and restauranteurs encourages others in Canada to make environmentally-wise seafood choices.

Seafood Choices Alliance

A group that encourages chefs, anglers, and citizens to make sound seafood choices. Check out the “seasense database.”

  1. Jackson, J.B.C. 1997. “Reefs since Columbus.” Coral Reefs 16(suppl.):S23-S32.
  2. Jackson, J.B.C. plus 18 co-authors. 2001. “Historical overfishing and the recent collapse of coastal ecosystems.” Science 293-629-638. editor’s note: Overview of published paper by CBC News at (accessed 20 November 2002).
  3. Pauly, D. 1995. “Anecdotes and the shifting baseline syndrome of fisheries.” Trends in Ecology and Evolution 10(10):430.
  4. Pauly, D., V. Christensen, J. Dalsgaard, R. Froese, and F. Torres, Jr. 1998. “Fishing down marine food webs.” Science 279:860-863.
  5. Purcell, J.E., W.M. Graham & H.J. Dumont, eds. “Jellyfish Blooms: Ecological and Societal Importance.” 2001. Proceedings of the International Conference on Jellyfish Blooms, held in Gulf Shores, Alabama, 12-14 January 2000. Hydrobiologia vol. 451, May 15 issue. Also available in book form from Kluwer Academic Publishers.


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