Work gets underway to keep Golden Bay TB free

18 September 2012

Work gets underway to keep Golden Bay TB free

The Animal Health Board (AHB) has begun vital aerial possum control across approximately 17,400ha of the Kahurangi National Park and surrounding farmland to prevent the spread of bovine tuberculosis (TB).

This operation forms part of a comprehensive TB control strategy prepared for the Tasman region. It supports the annual ground maintenance undertaken in the area by establishing a buffer against the potential reinvasion of infected possums into the greater Golden Bay area. Thanks to an intensive programme of herd testing, movement restrictions and large-scale possum control there are currently just two TB-infected herds in Tasman region, and none in Golden Bay. But that doesn’t mean there isn’t a risk. The same strain of TB has been found in possums, cattle and wild pigs from Karamea, Murchison, Wangapeaka Valley, the Baton Valley, Upper and Lower Moutere and Golden Bay. These areas all border on to the Kahurangi, indicating that it is a major reservoir for the disease.

The only thing keeping the region’s 1,600 domestic cattle and deer herds safe from this significant source of TB has been the creation of a buffer zone. In this buffer, possum numbers are maintained at extremely low numbers (just one or two animals per 10 hectares) to prevent TB spreading and cycling within the possum population. Until the disease can be eradicated completely from the Kahurangi, these continually-maintained buffers are the most cost effective way of protecting the region’s $500 million-a-year pastoral economy.

A pre-operational trend monitor conducted in 2011 in the original Golden Bay aerial treatment block returned a high pre-monitor Residual Trap Catch Index (RTCI) of 6.05%. This result shows that possum densities are increasing in the bush and bush pasture margins within this block. This operation will ensure that a low and even possum population of <2% RTCI is maintained reducing the risk of vectors interacting with domestic stock.

Due to the rugged nature of the terrain and the inaccessibility of this block, aerial application of biodegradable sodium fluoroacetate (1080) is the preferred control method. Using aerial 1080 to control possums has the added benefit of controlling other pests, such as rats and stoats, which pose a major threat to New Zealand’s native animals and plants.

Watch a short video of farmers talking about how and why we need to control TB in the Tasman District http://www.youtube.com/watch?v=lUyzBXdnZF4&list=UUgLOq9Cs9qb-dcTKJTtM-FQ&index=2&feature=plcp

Additional information

The operational area includes the Richmond Hill and the McGregor Gully. It is bound by the Pupu Valley Road and includes bush above the farmland of the Aorere Valley through to the Heaphy Track.

This particular operation was last flown in 2002. The general timeframe between aerial operations is five years. However, the overall success of the Tasman vector control programme has ensured that possum densities have remained low in this area for the past 10 years.

Ground control will be undertaken on approximately 10,000ha and aerial control on 17,409ha of the area.

Bait containing biodegradable sodium fluoroacetate, or 1080, will be applied at 2kg per hectare. This equates to around four baits in an area the size of a tennis court.

Each pellet contains 0.15 per cent sodium fluoroacetate. Toxic pellets are dyed green and flavoured with cinnamon to repel birds.

Helicopters will apply all bait using GPS technology to ensure accurate bait application and avoidance of agreed exclusion areas.

The operation was pre-fed (using non-toxic cereal bait) to increase the up-take of the toxic pellets by possums and overcome any bait shyness.

Warning signs will be placed at all main access points to the operational area. Anyone entering the area must heed the warnings on these signs.

While 1080 poses a potential risk to working and domestic dogs, accidental deaths can easily be avoided if domestic animal owners understand the risks and take sensible precautions. Muzzling dogs, feeding them before going near poisoned land and keeping them under observation can also reduce the risk of scavenging. Local vets have been notified about the operation.

The relevant Tasman District Council, Department of Conservation and Ministry of Health consents have been obtained. Water will be monitored as per the Ministry of Health guidelines.

More than 20 water samples were taken following aerial TB control operations in the West Coast/Tasman region last year. All tested negative for traces of 1080.

From September 1990 to February 2011, 2537 water samples have been tested by Landcare Research after aerial 1080 operations – none of those taken from drinking water supply contained any trace of 1080 at all.

The recent independent PCE report into the use of 1080 concluded that the poison posed no threat to either drinking water or freshwater ecology, and does not endanger people provided it is used as prescribed in regulations.

In the 60 years of 1080 use in NZ there are no recorded deaths associated with consuming toxic baits from the field; drinking water or eating wild food after a 1080 operation, and that the risk of illness is “very small”.

ENDS

© Scoop Media