Here's what the authors make of this observation that the level of the cave floor has dropped roughly one meter in just over half a century!
These are sobering observations about the potential impact of uncontrolled tourist visits at archaelogical sites. First, there's the clear conclusion of a one-meter drop in floor level over 50 years. More alarmingly, the most recent 50cm drop took place between 1988 and 2004, or 16 years. This means that the rate of tourism-mediated erosion has tripled relative to what it was between 1952 and 1988, in tandem with increasing peaks in the numbers of visitors at the site (Rossi and Webb 2008: Figure 2).
"Comparison of photographs we took in 2004 and 2006 showed that the shape of the entrance had changed; prompting us to research datable pictures of Mulka’s Cave on file at DIA. The resulting figure (Figure 3) shows that between 1952 and 1988, 0.5m of sediment was lost. By 2004, another 0.5m of deposit had disappeared. That erosion was accelerating is shown by the amount of sediment lost between 2004 and 2006. Had the walkway not been installed, erosion would have continued unabated because the deposits outside the cave were probed to a depth of -1m, without reaching bedrock."
"We attribute this erosion to trampling (Rossi & Webb n.d.). There are few places within Mulka’s Cave where visitors can stand comfortably to view the artwork because it is full of boulders (Figure 4); while the floor at the base of the rock pile measures 2 x 7m. These limitations became a problem with increased tourism, particularly visits by commercial tours. These groups often comprise 30 people, two of whom are crowded into each square metre of floor space. We believe the resultant trampling has eroded 1m of the cave deposits in 50 years. That sediment is now spread over the slope outside, but the stone artefacts it contains lack stratigraphic context." (Rossi and Webb 2008)
This raises the age-old question of what the interface should be between archaeology and the public. Much archaeological research is financed by public funds of one sort or another, and archaeologists can thus be argued to have some kind of obligation to make the fruit of their work available to the public. The problem, of course, is how to do this.
There is a lot to be said for doing for science in the interest of furthering science, in the sense of refining of our understanding of various phenomena even if this understanding cannot be immediately be translated for the public at large. On the other hand, we also have a duty to make the public appreciate the importance of publicly-funded research, in this case archaeology. This is made especially salient for archaeology due to the public appeal of archaeological research and the fact that it takes place 'in the real world', that is in space most people can access and occasionally even see as part of their lived landscape. In other words, archaeology can take place, quite literally, in your backyard, making this kind of research immediately engaging to contemporary people, at least on occasion. This is a far cry from most laboratory research where unquestionably important discoveries are made in contexts far removed from people's everyday reality.
While I think public education in archaeology and history is very important, I'm still open about whether this is best achieved through access to data, access to material, or access to sites. Access to data is a great thing, and potentially the easiest of the three to effect. However, archaeological data can take a very long time to analyze fully, resulting in delays in publication and therefore in public dissemination. Additionally, archaeological data are unlikely to be the easiest to digest for the untrained public, even a comparatively educated one.
Access to materials is perhaps the best way to make archaeology accessible and "tangible" to the public at large. The conservation and display of artifacts in museums is a tried, tested and true method of doing this, provided this is done well. Badly organized displays do very little to effectively carry across the importance/relevance of given archaeological collections.
Access to sites is much more tricky - visiting a site is unique manner of experiencing what 'doing archaeology' might be like, albeit very superficially. Visiting Paleolithic sites was certainly a formative experience for me, on at least one level. Visiting ruined cities, etc, also can give a sense that "people in the past" were a lot more like you and me than one might otherwise think, which is a good realization for anyone to have in an age of growing intolerance. However, while a one-off site visit may well convey the excitement of 'doing' archaeology, it transmits little to none of the tediousness that can characterize actual fieldwork, where you might be stuck working in the same square meter unit for days on end (see this post for more on this and another one by Kris Hirst). Personally, this was something I only learned when I finally got to do fieldwork, and that's coming from someone who loves being in the field – imagine what it must be like for people who don’t enjoy digging that much!
On top of that, as Rossi and Webb’s study demonstrates, unchecked tourist access can have serious impacts on the integrity of the archaeological deposits remaining at a site. This can be true of even extremely modest and highly controlled visit regimens, as the ongoing Lascaux crisis demonstrates. I’d surmise that even very large, very resilient sites (e.g., cities, temples, and the like) deal with very similar issues albeit perhaps at a different scale. Allowing the public to visit sites is thus fraught with conservation issues, but also a unique way of making people "experience archaeology" first-hand, resulting in a sort of tug-of-war over the value of making sites accessible to visitors. That said, I’m still not sure either is necessarily the best way to get across why archeology is important as opposed to simply being a cool thing to research.
Rossi, Alana M., and R. Esmée Webb. 2008. The erosive effect of tourism at an Aboriginal rock art site on the western edge of the arid zone in south-western Australia. Antiquity 82 (315): http://www.antiquity.ac.uk/ProjGall/rossi/index.html.