Dr Charles Eason has this morning received a New Zealand Science and Technology Silver Medal, awarded by the Royal
Society of New Zealand to recognise outstanding scientific or technological research that has made a significant
contribution to New Zealand society. Only five such medals are conferred in any one year.
The medal was presented by the Minister of Science, Pete Hodgson, at Landcare Research in Lincoln.
Dr Eason moved to New Zealand from the UK in 1989, and changed his career focus from drug discovery and evaluation to
environmental research. He is now a toxicologist at Landcare Research, where two years ago he established CENTOX (the
Centre for Environmental Toxicology) at Lincoln, to develop a new approach to risk evaluation of pollutants.
Dr Eason has been particularly involved with research into the effects of two widely-used pesticides, sodium
monofluoroacetate (1080) and brodifacoum. It is a measure of both his mana and his scientific impartiality that his
findings have been used to bolster the arguments of both opponents and proponents of the use of 1080. His
non-confrontational manner and his insistence on science instead of emotion in public discussions has done much to raise
the level of debate in the community. Users of 1080 are now very much better informed of its toxic effects, and with
more than 60 publications on 1080 by Dr Eason, New Zealand now has a much better idea of its long-term effects on the
environment.
Dr Eason has also shown that unlike other poisons, brodifacoum at sub-lethal doses persists in the liver, and because of
that tends to accumulate in the food chain. This research has led to restrictions on the use of the poison both here and
overseas.
A second Landcare Research scientist will also receive a New Zealand Science and Technology Silver Medal at a ceremony
at a later date.
Dr Phil Cowan is a leading researcher into the science and practicalities of possum control. He is the Programme Leader
for Landcare Research's $2.8 million programme, Mitigating Mammalian Pest Impacts, and the Director of Research
Operations for the Marsupial Cooperative Research Centre, a trans-Tasman consortium of four Australian research
institutes and Landcare Research.
Though the impact on of possums as leaf eaters of forest canopies was well known, Dr Cowan was the first to seriously
investigate their impact on native flowers, fruits and invertebrates. He showed the effect that possum browsing on
flowers has on native tree fruit production, and this has led others to investigate the pests' effect on plant
regeneration and on competition with native animals for food.
Perhaps his most public contribution to possum control has been the eradication of the pest from Kapiti Island, an
achievement widely considered at the time to be impossible. The success of this six-year-long programme in the 1980s led
to a major change of managerial philosophy in the Department of Conservation, which has now eradicated possums from a
further 14 islands.
Dr Cowan has also researched ways of reducing the efficacy of possums as vectors for bovine tuberculosis (Tb), giardia
and cryptosporidium. One study found that Tb distribution is independent of population density, a finding with
implications for buffer zone methods of Tb control. Dr Cowan has also produced an improved electric fence for possum
control, and has led the first comprehensive study of possum parasites and diseases in New Zealand.
One such parasite shows great promise as a vector for biological control of the pest. Dr Cowan's research into possum
mating and lactation behaviours is also of importance in this field.
Photo: Dr Charles Eason, receiving his award from the Minister of Science, Pete Hodgson, this morning.
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