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Perspective: How long can biodiversity baselines be shifted?

October 18, 2013

In this perspective, Nicolas Bailly, Biodiversity Informatics Scientist at WorldFish and BioFresh team member points to discussions of modern scientific concepts in an 1866 book on French fishes.  He asks readers of the BioFreshblog if they know of other old literature discussing similar topics.

Charles Émile Blanchard

Charles Émile Blanchard

Reading through some old literature on freshwater fishes, I found a book published in 1866 on the freshwater fishes of France by Émile Blanchard, a professor at the Muséum National d’Histoire Naturelle in Paris.

I must admit I had never encountered it before, but it was well worth a read. The first pages have an extraordinary and strangely modern flavor in the context of BioFresh – and the sad reality of freshwater ecosystems worldwide. In particular, Blanchard discusses three very current concepts.

  1. The shifting baseline concept

[…] old fishermen remember a time when their nets brought heavier loads, when fishing provided better livelihood.

  1. The ecological foot print of cities

Finally, there was not [in the remote past] these large cities that attract people and consume much of what is produced afar.”

  1. The lack of long-term monitoring and data series

We cannot, in truth, judge with absolute certainty the degree of fish abundance in ancient Gaul.”

  1. Shifting baseline

The “shifting baseline” concept was developed by Pauly (1995): when we try to reconstruct past biodiversity, to draw a baseline for measuring biodiversity losses, we always think about the biodiversity status when we were young, or at the most, as described by our (great-)grand-parents. But previous generations have done the same thing. So the baseline we try to set up is constantly being redefined by successive generations, because no one actually succeeds in restoring biodiversity to their baseline. The text of Blanchard written 150 years ago is a perfect illustration.

Now the question that comes immediately in mind is: if there were the same complaints 150 years ago, perhaps started well before (there are texts on regulation of continental water fisheries known from the 15th century), how is it possible that there are still fish in our (European) rivers? Are scientists wrong when they foresee the loss of most of our biodiversity? Are their forecasts reliable?

The answer is not that simple, and requires hundreds of thousands if not millions of data (for example, the global fishery catch reconstruction performed by the Sea Around Us Project). It is the aim of the BioFresh portal to make these data available to scientists so they can improve their models, interpretations and predictions.

  1. lespoissonsdesea1866blan_0007Ecological footprint

Developed by Rees (1992), this is a measure of society’s demand on natural resources and ecosystem services. While we can actually see the demand in the countryside where villages are closely surrounded by nature, it remains virtual for citizens in megacities. Almost all what is consumed is seen only in human-built artifacts (food in supermarkets, water in pipes, power in wires, etc.). BioFresh has not directly addressed ecosystem services, but all the work done in this area can be used to help in valuing freshwater ecosystems.

  1. Lack of long-term data series

When a young biodiversity scientist starts to search for data to build or test hypotheses, it is always a shock to discover that 1) very little is available; and 2) very few long-term monitoring programmes exist. There are particularly few long-term data series available for freshwater (e.g., Allan et al 2005).

Past generations have not managed to set up long-term observatories of biodiversity (in part because it’s hard to automate, unlike physical oceanography or meteorology). My generation hasn’t either, and some good initiatives like LTER (Long-Term Ecological Research) are drops in the ocean…or rather, in freshwater lakes, from a BioFresh perspective!

One of the results of BioFresh data gap analysis is that to make clear that these data must be acquired under planned activities: gathering data from a lot of sources is not usually enough to constitute a proper dataset for models that need many records, close together in space and time.

IMG_4760I would propose the concept of “shifting responsibility” to describe the fact that no generation so far had the vision (and/or the courage) to set up such long-term biodiversity monitoring for the future. Or perhaps our generation could succeed with a proper organization of citizen science (science participative in French).

Are there other such concerns published in documents before the 20th century?

Is this just one book – an idea of a single man in those times, or did it express the concerns of a community of scientists or other visionaries?

I would like to hear about other concerns expressed before the 20th century in books, articles and reports, and from other countries. Please share and comment such references in the blog if you know about them (or send the reference to me by email). If there are enough, it could be worth opening a group in a reference management system such as Mendeley or Zotero. For my translation of the first section of Blanchard’s work, see the PDF file here.


Allan J.D., Abell R., Hogan Z., Revenga C., Taylor B.W., Welcomme R.L. and Winemiller K. 2005. Overfishing of Inland Waters. BioScience 55(2):1041-1051.
doi: 10.1641/0006-3568(2005)055[1041:OOIW]2.0.CO;2

Blanchard, Émile, 1866. Les poissons des eaux douces de la France : anatomie, physiologie, description des espèces, mœurs, instincts, industrie, commerce, ressources alimentaires, pisciculture, législation concernant la pêche. Paris: J.B. Baillière & Fils.

Pauly, D. 1995. Anecdotes and the shifting baseline syndrome of fisheries. Trends in Ecology & Evolution. 10(10):430.

Rees, W.E. 1992. Ecological footprints and appropriated carrying capacity: what urban economics leaves out. Environment and Urbanisation 4(2):121–130.

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