No practical alternative

It will be a sad day for the birds and bush of New Zealand if 1080 use is banned or severely restricted before a practical alternative is found.

It could also be an expensive and potentially ruinous day for farming if this effective tool against Tb and rabbits is prohibited. The poison, including its distribution from the air, remains vital in the fight against possums.

It remains, in the telling words of a 2007 Environmental Risk Management Authority (Erma) review on 1080's use, a "necessary evil".

Opposition to 1080 is on the march, growing with each passing year.

Last week, about 300 protesters vented their strong concerns in Hokitika, and calls to have it banned have spread to officialdom as evidenced by the views of at least two district councils, Westland and Taupo.

In Dunedin last year, Cr Fliss Butcher claimed the Erma findings were "rigged". She signalled her wish for community debate on the issue, saying 1080 should not be used.

The widespread use of a powerful poison has become highly emotive.

On the other side of the debate, not only are the Department of Conservation and Federated Farmers emphatic about the vital and central place of 1080 in the pest killing arsenal, but so too is Forest and Bird.

The possums, stoats and rats which decimate bird life must be controlled over massive areas even when this means that in the short term birds are killed as well.

Extensive monitoring over decades has shown bird numbers rise rapidly after 1080 has done its deed.

The New Zealand bush, far too quiet all too often, comes alive again with birdsong.

The beech understorey, after decimation by possums and deer, sprouts with vigour.

Even the Green Party, despite some of its supporters being in the anti-poison camp, acknowledges 1080 - and aerial application of 1080 - is essential for protecting native plants and animals in remote areas.

At the same time, the party has called 1080 use a measure of last resort.

More labour-intensive (and therefore more expensive) control is encouraged wherever possible.

Bounties on possums failed in the 1950s: possums continued to flourish.

Bounties can never succeed in distant, rugged parts, and "farming" possums is encouraged in more accessible places.

Also, deadly stoats and rats will not be caught through possum-killing subsidies.

Similarly, operations by helicopter, like that in the Arawhata Valley in wild country well west of Wanaka in 2008, are emphatically the only feasible delivery method.

The upper reaches of such locations are days and days from the nearest road or even 4WD track, and travel is often precipitous or through difficult-to-penetrate scrub and bush.

The name of one 3km stretch of the Arawhata River says it all - 10-hour Gorge.

It should also be acknowledged that 1080, which has been used since the 1950s, does break down quickly in the environment, albeit having the potential to last some time in carcasses; that there are no recorded instances of significant harm to people; and that the direct consumption of large amounts would be needed for a fatal human dose.

Tb endures as a major threat to cattle exports, despite 1080's role in helping to kill possums as carriers of the disease.

Long-running efforts on several fronts have, in fact, led to large areas becoming Tb free.

It would be crazy to relent and backslide on that effort.

The good news is that ways have been developed to apply smaller amounts of 1080 to do the same job, and that deer-repellent bait has been developed for use in special recreational hunting areas. Disappointingly, science is still a long way from discovering a practical alternative.

The research must continue because even 1080's strongest proponents should acknowledge dangers in its use.

The cries of the anti-1080 brigades are shrill and and persistent, and their fervour, feeling and commitment is evident.

It behoves others, and especially those in positions of authority such as district councillors, nevertheless, to see beyond this emotion and be willing to weigh up fairly and dispassionately the advantages and drawbacks to 1080's use.

They may well then - like us - retain misgivings, but will see that there is no practical alternative.