KERRY O’BRIEN: A report commissioned by a small group of oyster farmers has reopened debate about the impact aerial spraying of pesticides and herbicides could have on waterways and public health.
The report has found that aerial spraying of private forestry plantations on Tasmania’s east coast was linked to a major oyster kill early this year, and possibly to the mystery illness which is devastating the Tasmanian devil population.
Some doctors have called for aerial spraying to be banned until the broader risks to public health can be properly assessed.
For its part, the forestry industry has welcomed an audit of its chemical usage, but maintains that aerial spraying poses no health or environmental threat.
Jocelyn Nettlefold reports.
JIM HARRIS, OYSTER FARMER: Well, you can’t help but feel angry and frustrated because, you know, I mean, collectively we lost here at Christmas time around about $1.5 million worth of stock.
JOCELYN NETTLEFOLD: For the oyster farmers at Georges Bay, on Tasmania’s east coast, it was a devastating blow – the sudden death of thousands of shellfish.
JIM HARRIS: These aren’t big businesses – they’re small businesses – and in an area like this, you know, we can’t sustain those sorts of losses.
JOCELYN NETTLEFOLD: Many began to suspect a link to the recent growth in the number of private forestry plantations around Georges Bay.
Aerial spraying of pesticides and herbicides made them wonder about the quality of the water running from the upper catchments.
So the oyster farmers commissioned Sydney water scientist Dr Marcus Scammell to investigate.
DR MARCUS SCAMMELL, MARINE ECOLOGIST: Initially we looked at the different types of practices in the catchment, but it wasn’t until we discovered that there was a helicopter accident where the helicopter had been using chemicals in aerial spraying that we really started to look at what was going on in the forestry plantations themselves.
JOCELYN NETTLEFOLD: While the pilot survived the crash with a broken leg, the spill of chemicals has reopened a sensitive public health debate.
Tests on the crash site revealed very high levels of the insecticide alpha cypermethrin, which is extremely toxic to marine life, and herbicides Atrazine and Simazine, which have been linked to tumours in mammals.
The Australian Medical Association has called for a ban on aerial spraying near water catchments in Tasmania until it’s proven to be safe.
DR ALISON BLEANEY, ST HELENS GP: How we can overcome having toxic chemicals put into catchments that drinking water comes out of?
JOCELYN NETTLEFOLD: Sydney GP Dr Mark Donohue has been studying the health effects of pesticides and herbicides for more than a decade.
DR MARK DONOHUE, SYDNEY GP: So if they get into the water supply or if there is a regular contact, the real risk is that in five, 10, 20 and 30 years’ time, we see cancer rates escalating.
EVAN ROLLEY, FORESTRY TASMANIA: We’ve done over 5,200 samples over the last 10 years and only three pesticides ever turned up.
That was Atrazine, that was nine years ago, and as soon as it turned up, we ceased using Atrazine.
JOCELYN NETTLEFOLD: While Forestry Tasmania is responsible for about 20 per cent of the water catchments in Tasmania, it’s not responsible for the private plantations at Georges Bay.
But spokesman Evan Rolley maintains the forestry industry should not automatically be blamed.
EVAN ROLLEY: I think the real challenge is to make sure there’s a full audit of all of the catchment, not just the forested part, but the agricultural and the urban part of the landscape.
DR DAVID LEAMAN, GEOHYDROLOGIST: People have just ignored the realities and the risks.
And we haven’t been careful enough.
We haven’t applied the duty of care.
JOCELYN NETTLEFOLD: Geohydrologist Dr David Leaman claims controls on aerial spraying aren’t being enforced.
DR DAVID LEAMAN: There’s certainly no real assurances about the dosage or the control of usage.
There are too many cases where sprays have gone over people’s roofs, where the water’s gone into their tanks, where people have been sprayed.
JOCELYN NETTLEFOLD: In the wake of the Scammell report, the Tasmanian Government has ordered that the local water supply around Georges Bay be tested for chemical residues.
PAUL LENNON, TASMANIAN PREMIER: Very serious allegations have been raised in the report, we accept that.
And we want them properly analysed and that is what we are ensuring will occur.
JOCELYN NETTLEFOLD: But humans aren’t the only mammals at risk.
Dr Scammell also found that aerial spraying may be responsible for a mysterious disease which is devastating the Tasmanian devil population.
DR MARCUS SCAMMELL: As it turned out, there was a strong correlation between the beginning of oyster problems and the beginning of the Tasmanian devil’s issues in terms of facial tumours and mortality.
JOCELYN NETTLEFOLD: Wildlife biologist Nick Mooney, who has been monitoring the decline in the devil population, believes aerial spraying can’t explain the extent of the deadly epidemic.
NICK MOONEY, FACIAL DEVIL DISEASE TASK FORCE: This coincidence, this correlation, it’s no surprise to us.
We do have devils with this disease in many areas that there’s been no spraying, so it’s not an exact overlay by any means, and there’s a lot other reasons we have to look into.
This has a priority but it has to compete with other issues.
JOCELYN NETTLEFOLD: The science within the Scammell report into the Georges Bay oyster kill will long be debated, but it will go down in history as a wake-up call to the issue of chemical spraying in Tasmania.
The report found the general breakdown in environmental protection and human health protection processes at every level of government.
DR DAVID LEAMAN: We’ve got to become more realistic and more caring about, one, the people that are affected by this, and then secondly, the long-term effect on the environment in which our children are going to have to live, so it’s people again.
JOCELYN NETTLEFOLD: The Tasmanian Government admits it does not know the volume of chemicals entering the state’s waterways.
It will start an inquiry by examining the records of spraying contractors to find out exactly what chemicals were discharged, where and when.