GIGO

Possum Peppering

Remember the TV show That's Incredible? It featured a whole host of amazingly incredible things, some of which were truly incredible or, rather, unbelievable.

It was with a certain sense of incredulity that I recently watched TVNZ's "Earth Care" segment on possum peppering. You may recall the piece we ran on this biodynamic approach to eliminating possums. Our June issue noted how possum testicles are burnt and the heavily diluted ash used as a repellent spray. It also noted that the Forest Research Institute had conducted the world's first scientific tests of peppering and showed, alas, that the claims could not be supported.

The FRI had been asked to run the tests partially in response to the strong public interest in peppering following a television item on its use by a Kaipara orchardist. TVNZ used the same clip eight months later in its "Earth Care" segment, with the claim that the very dilute solution would also cause infertility in the possums.

Like most people, I tend to use television as a news source. Like most people, I tend to assume that material presented as fact is, in fact, fact. We are shown pictures of rainforests being logged, we are shown diagrams of the ozone hole, we believe what we see and we act on what we are shown.

TVNZ had been informed of FRI's work, both through our pages and by the institute itself. Perhaps understandably, they didn't give the news much, if any, coverage -- negative results don't make good television. Negative results are part and parcel of good science, however.

TVNZ's rationale for running the item was that the gentleman concerned believed possum peppering worked, so they felt justified in promoting this claim. No questions asked. I wonder if TVNZ would be interested in telling us that the world is flat -- there are people who fervently believe that -- or in covering the recent sighting of Elvis in Auckland...

To make matters worse, this justification was given by the Natural History and Science Unit, which is producing the segments. I have had the greatest respect for the unit's work in the past, but their credulity in this area now makes me wonder what other unsupported assumptions and articles of faith appear in their apparently scientific coverage.

Credibility is an important virtue and, like any virtue, is all too easy to lose and very difficult to regain. Environmental issues, raising passions as they do, are particularly vulnerable to incredible claims. The various environmental problems facing us, both within New Zealand and internationally, are too important to be treated in such a cavalier fashion.

Whether it's possum peppering or fears of chemical contamination, once doubts are raised about the veracity of a claim, then the organisation making those claims has a much harder time convincing its audience that it really knows what it's talking about. Make too many incredible claims, and you'll be classed alongside Elvis-sighters, and rightly given about as much attention.

Vicki Hyde is the editor of New Zealand Science Monthly.