Viewpoint

Assessing
Environmental Risks

The stillbirth of a potential freshwater crayfish industry north of Auckland a couple of years ago had aquaculturists claiming government foul play. The government had, after all, allowed the marron to be imported and bred up. It then decided to change the rules and refused the sale of second generation stock. It was decided -- belatedly -- that the scheme was too environmentally risky.

The marron exemplify ad hoc environmental management. Initial permission to import came because of a lack of knowledge of environmental risks and weakly-worded legislation that left nobody sure about what could -- or couldn't -- be banned. Finally, what really weighed against the marron wasn't astute environmental risk assessment, but political risk management. Even if the probability of escape and establishment was small, the political fallout of being seen to take such risks would be too hot to handle.

Demands for environmental risk assessments will increase under the Resource Management Act (RMA). The demands for scientists to make decisions aware of the social milieu will increase. This is particularly so as the Ministry for the Environment says that the RMA's "sustainable management" of resources has to be seen in the context of sustainable development -- ensuring all members of society have their needs met and ensuring that all development is socially, economically and environmentally sustainable.

A likely role for scientists is to predict future impacts of development policies, to encourage the rehabilitation of damaged ecosystems, and mitigate or avoid ecological harm. But overriding any such presumed scientific interests is the threat of having research agendas decided by lawyers and legislators.

For example, freshwater benthic macroinvertebrates can be used as indicators of a decline in water quality. Biologists may distinguish between natural cycles in relative species abundance and the impact of human activities upstream. However, it may be impossible to prove this in the courts. Biologists will always have to confess that not only is the proof equivocal, but the impact could be temporary and reversible.

Thus, a water right might be granted, or continued, when there are strong suspicions the catchment will continue to be degraded, particularly when other social outcomes are taken into account.

Such arguments are akin to arguing about angels fitting onto the heads of pins. The present economic system is already known to have degraded the environment. As with farmers and marginal land development, the undesirable impact of a specific industrial practice may be established well before a scientific debate in a court of law can prove it to be so on a balance of probabilities. The danger in pursuing the burden of legal proof is seeing research priorities being dictated by legal, not scientific, case history, as New Zealand scientists' energies are frittered away trying to score Pyrrhic legal victories.

Instead of establishing scientifically sound rules for the development of district and regional plans, and national policy statements within which resource development must occur, scientists are supplying evidence as to why resource use should continue within the guidelines drawn up by a largely political -- rather than largely scientific --  process.

Therefore, in the absence of evidence to the contrary, economic "development" could well continue more or less as before, despite the RMA and the recognition that ecosystems cannot sustain such development. This is because there may be insufficient evidence that a particular specific activity is contributing to the overall destruction of a self-sustaining environment. Indeed, it may not. Strong evidence either way would prevent proponents and opponents wasting time. Instead, opponents will oppose because there is insufficient evidence to prove that it isn't harmful, and proponents will often win because of insufficient evidence showing it is.

The evidence is lacking because too little is invested in research to understand the basis for the "creation" of wealth (a phrase which in itself defies the laws of physics). And of course, science can never know enough to predict anything without varying degrees of error. Scientific debate is often over those degrees of error. Society's interpretation of the ensuing law court debate can mistake this for a debate over the mechanism itself. Thus, when debating whether to dump Port of Auckland waste into the Hauraki Gulf, it comes down to saying there is a greater probability the ecological harm will be acceptable than not. That there will be ecological harm cannot be debated. But it ends up as being seen as saying just that.

An example of the need to establish ground rules is the Protected Natural Areas Programme. Designed to preserve ecologically distinct ecosystems and improve the chances of survival of indigenous communities of species, success depends on factors including the size of the reserved area, the proximity of reserved areas, substrate heterogeneity and level of management. But the reality of capturing remaining natural areas outside the Department of Conservation's managed estate involves identifying a willing "seller", rather than necessarily identifying what areas of the unprotected natural estate would really benefit from being protected. Decisions have to be accurate (such as weighing up opportunity costs against conservation value) and fast (because inhabitants may be lost while prioritising ecosystems for safeguarding).

Given that estimating the minimum number of individuals needed to maintain a viable population is an extremely complex issue, this ad hoc approach may be ultimately inefficient. There is the danger of winning the battle to establish a comprehensive system of reserves through political action, but losing the war as a lack of ecological understanding leads to isolated, island reserves gradually deteriorating through attrition.

Stephen Knight is an environmental scientist and journalist working in Auckland.