Research in biosecurity covers many different branches of science, as well as economics and sociology to understand the impacts of an introduced pest. Scientists are involved in developing methods to detect foreign organisms, understanding how introduced organisms grow and spread and developing ways to control or eliminate the unwanted pest.

Sometimes it is important to identify where an introduced pest came from, or to separate closely related speciesGenetic fingerprinting or examining the distribution of natural radioactive isotopes can help with this.

Scientists also work on new ways to eliminate pest species, for example, developing poisons that target only the pest species or by identifying diseases of specific species that can be used to control pest numbers. There may be other organisms that specifically kill pest species, for example, certain predatory wasps lay their eggs in other species of insect, and the developing larva then kills the host.

The water-borne diatom alga didymo has quickly spread into rivers in the South Island since it was first detected in 2004. Scientists from local councils, the Department of Conservation (DOC), Ministry of Agriculture and Fisheries (MAF), Biosecurity, National Institute of Water and Atmospheric Research (NIWA) and Fish and Game NZ are involved in monitoring rivers to work out where it has spread to, and how it is doing so. Scientists are also involved in investigating ways in which it can be controlled and the effect it has on aquatic life. Public awareness campaigns are important in informing people on the risks and of the procedures needed to prevent boaters and fishers from spreading the algae.

New biotechnology techniques allows novel methods for dealing with pests, for example, New Zealand scientists at Landcare Research are working on a vaccine that would make possums infertile. The target of the vaccine would be proteins involved in reproduction, which are found only in possums, so that risks to other species are reduced. Research also has to be done on how to deliver new vaccines and poisons and on predicting how combining different control methods can be more effective.

A great deal of care has to be taken to examine all possible risks in producing biological controls, as past experience shows that release of one organism to control another can have unexpected and damaging knock-on effects (such as the release of stoats to control rabbits).

Find out more about investigations into using biological control to combat our possums probelm in this article, Biological control of possums.

    Published 9 September 2008