Estimating the proportion of Archey’s frogs in the Wharekirauponga mine vibration footprint 17 Estimates of the Archey’s Frog Population within the Vibration Footprint There is no evidence on whether vibrations from underground mine blasting affect Archey’s frogs. However, at Golden Cross underground mine Archey’s frogs have persisted in areas subject to vibration velocities of ≥2<4 mm sec-1 indicating that they can tolerate vibrations of this magnitude[31]. In the absence of evidence about the effects of stronger vibrations a precautionary approach has been adopted with the assumption that vibrations higher than ≥2<4 mm sec-1 could have adverse effects on Archey’s frog populations[31]. Vibrations from mining activity with velocities ≥2 mm sec-1 will be apparent in three catchments (Figure 8): Wharekirauponga, Waiharakeke, and Mataura. The footprint of vibrations ≥2 mm sec-1 includes 315 ha of frog habitat, with 302.6 ha in the Wharekirauponga catchment and 12.3 ha in the Waiharakeke catchment (Table 10). The vibration footprint in the Mataura catchment is around the mine entrance, outside of frog habitat and almost entirely in farmland. In the Wharekirauponga catchment, the footprint encompasses 156 ha of mixed vegetation at lower altitudes containing manuka-kanuka scrub and general hardwoods forest (M1, N5 & M, n5), with area of historical disturbance by human activities; and 146 ha of relatively intact mixed kauri forest, with native scrub or podocarp-hardwood forest (N2, m6 & N2, n3a) at higher altitudes. The vibration footprint in the Waiharakeke is also in frog habitat, encompassing 6.9 ha of (N3a) forest and 5.4 ha of (N2, N3a) forest. The 315 ha area of frog habitat in the ≥2 mm sec-1 vibration footprint is 0.54% of the total area of frog habitat in the 578 km2 main block of contiguous habitat >200 m a.s.l. with historical Archey’s frog records up to 2019. Figure 8 The extent of the predicted vibration footprint of the proposed Wharekirauponga mine. Contours of the vibration levels delineate the maximum extents of seven vibration intensity levels.
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