Alien Species.vp - IUCN

Paula Warren
will have different perceptions. Education processes will reduce the degree of inconsistency
between the two risk assessments, but it is unlikely that education can completely remove it.
Where the scientific assessment of risk has a high level of uncertainty, making a judgement
based on that assessment which is contrary to the public perception would be likely to result in
societal opposition. In these circumstances, the decision should probably be treated as a
political decision.
Risks to certain values (e.g., cultural values, ethical values, intangible values) may be very
difficult to assess in a scientific way, and the perceived risk may be the only valid assessment.
These factors are difficult to incorporate into decision-making, since to rely totally on the
assessment of risk by the affected party would be to assign accountability to that party. That
would be inappropriate if that party is not the decision-maker under law.
Dealing with uncertainty
Uncertainty is a fact of life in assessing costs and benefits of alien species issues. It may arise
from a lack of information or from a lack of agreement among experts on how available
information should be interpreted. The need to apply a precautionary approach to these
uncertainties is widely recognized in international and New Zealand law. Where the decisionmaker’s
professional judgement is that they can’t be satisfied on the information available that
an importation will be safe, or that not eradicating a pest is acceptable, they would ordinarily
deny approval for importation or eradicate the pest. It may be appropriate to make an initial
decision and then seek further information to reduce the level of uncertainty, allowing an
alternative decision to be considered at a later stage.
If a decision is made to accept a level of risk, but knowing that there is a significant
uncertainty in the information on which that decision was based, the decision-maker should
take steps to monitor the situation, seek further information, and if necessary reverse the
decision if subsequent events show that the decision was wrong. The degree of uncertainty that
is acceptable would depend on the severity of possible negative effects, and the likelihood of
reversing those effects (e.g. the likelihood of eradicating a species if it proves to be invasive).
Sharing the costs
As well as assessing whether costs are acceptable, it is also necessary to determine who will
carry those costs. This has several key elements. It may be possible to alter the nature of the
costs and in so doing alter the affected party. The economics term “internalisation” is often
used for this process. For example, import health standards that require certain treatment of a
risk good before it leaves its port of origin (e.g., fumigation of a container) may impose a
financial cost on the importer, but remove or reduce an environmental risk/cost for New
Zealand society. In effect, the cost of importation has been transferred from New Zealand
society and environment to the importer. The cost has been internalised.
Where an action has a direct financial cost (e.g., control of a pest species in New Zealand, or
of a decision-making process), a number of parties could bear that cost. For example, a
statutory process is in place for developing national or regional pest management strategies that
identify those pests that the community should be collectively controlling. Once a strategy is
approved, the management authority which prepared it has a wide range of powers to achieve
its implementation, including requiring landowners to carry out pest control work at their
expense. In effect, the strategy provides a mechanism for ensuring co-ordinated control action
across all landowners/sectors, and allocating the costs of control efficiently between those
exacerbating the problem and those benefiting from control. The way costs are allocated should
provide the right incentives to minimise the problems.
110