The annual Golden Gecko Awards for Environmental Excellence run by the WA Department of Mines and Petroleum welcomed a real gecko this year.
Mining-related surveys identified two new lizard species in the Pilbara: the mosaic desert skink and the northern beak-faced gecko.
This discovery was a reminder of the significant role and responsibility that the resources sector plays in contributing to the scientific understanding and stewardship of the unique Western Australian environment.
Minimising the impacts of onshore exploration for minerals or petroleum was the main focus of this year’s award entrants, including Crosslands Resources which received a Golden Gecko.
Crosslands won the award for the innovative research it commissioned to measure the impact of drilling vibrations on a protected spider species at the mining company’s Jack Hills Iron Ore Project.
Short range endemic surveys in 2007 by Crosslands Resources at Jack Hills identified new populations of the Schedule 1 Shield-back Trapdoor Spider Idiosoma nigrum.
The research focussed on the Jack Hills mine site but also involved verification at fellow miner Sinosteel Midwest Corporation’s Weld Range Iron Ore Project.
Both projects are between Cue and Meekatharra.
Due to the uncertainty regarding the impacts of exploration on the spiders, a 200m buffer distance was required between spider burrows and any drilling activity.
Crosslands Resources manager, environment and approvals Dr Lara Jefferson sought a consultant that could deliver an ‘outside-the-box’ approach to assess the effects of past and new exploration drilling programs.
Jefferson eventually engaged Phoenix Environmental Sciences for their survey design that had two key innovations.
One was the use of fibre optic technology to allow the for the observation of spiders in burrows without digging them up.
The second was the design and development of a Vibration Simulation Device (VSD) that provided vibrations equivalent to drilling.
This device allowed the survey to be undertaken with no new clearing as it was much more mobile.
Phoenix approached the research in two ways.
Firstly, it determined the historical impacts of exploration activities on the local populations of the species.
The research found that there was no discernable difference between the presence or absence and population structure of the populations within and outside the 200m disturbance buffer that the WA Department of Environment and Conservation had placed on Crosslands’ and Sinosteel’s activities.
To prove this Phoenix sourced and modified highly portable fibre optic viewing devices that made it possible to observe the species within its burrow with no disturbance to the conservation significant species.
The second approach investigated the immediate impacts from vibrations caused by drilling and other ground disturbing activities on the survival of the species.
The solution: Phoenix engineered the VSD using an offcentre vibratory motor coupled to a heavily modified skidsteer loader bucket.
The vibration output was finely controlled using a speed controller.
The vibration ‘fingerprint’ of the VSD was then calibrated against in-field measurements made of RC drilling rigs.
Once calibrated the VSD was operated within 25m, 50m, 75m and 100m of the spider populations.
This was repeated across all known populations of the species at Jack Hills.
The result was no observable response impact to the spiders from the vibrations.
Phoenix Environmental Sciences managing director and senior invertebrate biologist Jarrad Clark said the aim of the research was to minimise the impact to the environment and the cost to the project.
“We had very few planned exploration drill holes in the vicinity of known spider populations, so our sample size was going to be too small to be scientifically valid,” Clark told Australian Mining.
“There were too many disadvantages to drilling additional holes for it to be feasible including additional impacts, cost, logistics and scheduling.
“The result was the VSD design concept, which was tested in Perth before deployment.
"It offered dvantages over using an actual drill rig.”
The VSD incorporated equipment that was readily available which removed the logistical and scheduling issues.
“The VSD is comparatively small and, therefore, highly manoeuvrable so we could access more remote spider burrows but also avoid the need for clearing for new access tracks or drill pads,” he said.
“The enhanced vibratory control options gave a superior data set and it was much cheaper to operate.
“Also, there was no drilling involved and, therefore, no need to return and rehabilitate holes.”
Clark said the innovative approach was driven by the need to employ ‘zero-impact’ survey methodology because they were dealing with a Schedule 1 species.
“The normal survey method of excavating burrows was out of the question,” he said.
“We also had to ensure scientific rigour with a survey method that would be robust, efficient, accurate as well as repeatable.
“The fibre optic monitoring technique was the most obvious solution as it involves using a down-hole camera on fibre optic cabling to carefully manoeuvre through the burrows and actually ‘sight’ the spiders in-situ.
“The method met all our criteria for scientific rigour, with the added bonus of being efficient, highly portable and cost-effective, it really was a win-win solution.”
Clark said the research project had some exciting environmental and project-specific outcomes.
“The project yielded a much larger, more robust data set for the Shield-back Trapdoor Spider in the Mid-West region, bringing more focus to monitoring and management of the species,” he said.
“It also provided the first empirical evidence that drilling vibrations have no discernable effect on these spider populations in Banded Iron Formations.”
The respective technologies also have many applications in mining and environmental management, according to Clark.
“The fibre optic technology could be used to monitor any burrowing species in a repeatable, accurate and, therefore, reliable way,” he said.
The VSD could also be used to assess vibration and noise impacts to other conservation significant species such as bats and near-surface subterranean communities, according to Clark.
“A fine level of control can be achieved, so the method offers a reliable way of testing multiple ranges of vibration.
Comparatively little is known about noise and vibration impacts compared to other impacts and we perceive there could be a demand for this sort of assessment in coming years,” he said.