Research Papers
Publications are a critical part of many of our research projects to provide clarity and demonstrate the quality of science completed by Verum Group. A selection of recent papers are below, and many more are available through our research gate links or feel free to contact our scientists directly. Use the search function to hunt through PDFs of our research papers.
Topics to explore: Ecology | Environmental Management | Geochemistry | Treatment & Rehabilitation
Ecology
Jahn, P., Cagua, E. F., Molles, L., Ross, J. & Germano, J. (2022). Kiwi translocation review: are we releasing enough birds and to the right places?. New Zealand Journal of Ecology 46, 1, 3454. doi:10.20417/nzjecol.46.1
What it's about:
Translocations of kiwi (Apteryx spp.) are one of the most common and growing types of conservation translocations in New Zealand. However, their outcomes remain mostly unpublished, which does not allow for sharing of lessons learnt from past developments. We reviewed 102 kiwi translocations from the 19th century until 2018, and identified factors affecting their outcome. Email Laura
Jahn, P., Ross, J., MacKenzie, D. & Molles, L. (2022). Acoustic monitoring and occupancy analysis: cost-effective tools in reintroduction programmes for roroa-great spotted kiwi. New Zealand Journal of Ecology 46, 1, 3466. doi:10.20417/nzjecol.46.21
What it's about:
Monitoring the response of wildlife populations to conservation management, such as translocations, is crucially important for assessing its effectiveness. Passive acoustic monitoring (PAM) is an emerging tool for monitoring cryptic and elusive species and is increasingly used in the management of kiwi. Email Laura
Jahn, P., Ross, J.G., Mander, V. & Molles, L.E. (2022). Post-translocation movements and ranging behaviour of roroa (great spotted kiwi, Apteryx maxima). Notornis 69, 3, 135-146.
What it's about:
Translocations are increasingly used in kiwi (Apteryx spp.) conservation management, and their outcome is largely influenced by post-release dispersal and survival. A translocation of roroa (great spotted kiwi, A. maxima) to the Nina Valley, near Lake Summer Forest Park, is the first reintroduction of the Arthur’s Pass roroa population. Email Laura
Bedoya, C. & Molles, L. (2021). Acoustic censusing and individual identification of birds in the wild. 14pgs. Preprint doi:10.1101/2021.10.29.466450
What it's about:
Individual bird calls carry information that can be utilized as an alternative to physical tagging of individuals. However, it is rarely used in conservation tasks despite rapidly-expanding use of passive acoustic monitoring techniques. Reliable acoustic individual recognizers and accurate quantifiers of population size remain elusive, which discourages the use of vocal individuality for monitoring, wildlife management, and ecological research. We propose a neuro-fuzzy framework that allows discrimination of individuals by their calls, the discovery of unexpected individuals in a set of recordings, and estimation of population size using solely sound.
Click here for Supplementary Information (Data) used in this paper. Email Laura
Dent, J. & Molles, L. (2016). Call-based identification as a potential tool for monitoring Great Spotted Kiwi. Emu, 116, 315-322. doi:10.1071/MU15079
What it's about:
This research has led to a 2020/2021 Verum Group project "Individual Recognition & Monitoring of Great Spotted Kiwi" led by Laura Molles. The study will hopefully pave the way for monitoring of the Great Spotted Kiwi population in a non-invasive manner, avoiding the need to capture the birds. Email Laura
Dent, J. & Molles, L. (2015). Sexually dimorphic vocalisations of the great spotted kiwi (Apteryx haastii). Notornis, 62, 1-7.
What it's about:
Kiwi (Apteryx spp.) are the most vocal of the ratites. Of the 5 Apteryx species only 2 have previously been subject to detailed vocal analysis: the North Island brown kiwi (A. mantelli) and the little spotted kiwi (A. owenii). This paper describes the vocalisations of the great spotted kiwi (A. haastii), the largest of the Apteryx species. Email Laura
Bedoya, C., Isaza, C., Daza, J. & López, J. (2014). Automatic recognition of anuran species based on syllable identification. Ecological Informatics, 24, 200-209. DOI:10.1016/j.ecoinf.2014.08.009
What it's about:
One of the earliest papers to report acoustic species identification with unseen or novel class discovery. Some key elements proposed in this research are used in our kiwi monitoring programme. Email Carol
Valderrama, S., Molles, L., Waas, J. & Slabbekoorn, H. (2013). Conservation implications of song divergence between source and translocated populations of the North Island Kōkako. Journal of Applied Ecology, 50, 950-960. DOI:10.1111/1365-2664.12094
What it's about:
This research investigated variation in song, and response to song, among source and translocated populations of the endangered North Island kōkako - combining together song, translocations, and conservation. Email Laura
Molles, L. & Vehrencamp, S. (2001). Songbird cheaters pay a retaliation cost: evidence for auditory conventional signals. Proceedings of the Royal Society of London, Series B 268, 2013–2019. DOI:10.1098/rspb.2001.1757
What it's about:
This research was an early and convincing demonstration of an important concept in animal communication. Email Laura
Environmental Management
Cavanagh, J., Pope, J., Harding, J., Trumm, D., Craw, D., Simcock, R., Weber, P., Webster-Brown, J., Eppink, F. & Simon, K. (2018). Mine Environment Life-cycle Guide: potential acid-forming and non-acid-forming coal mines. 178 pgs. Christchurch: CMER.
What it's about:
The Mine Environmental Life-cycle Guides (MELGs) have been developed as part of a collaborative research programme to assess and predict the environmental impacts of mining operations for New Zealand’s geology and environmental conditions. Email James and Dave
Cavanagh, J., Pope, J., Simcock, R., Harding, J., Trumm, D., Craw, D., Weber, P., Webster-Brown, J., Eppink, F. & Simon, K. (2018). Mine Environment Life-cycle Guide: epithermal gold mines. 173 pgs. Christchurch: CMER.
What it's about:
The Mine Environmental Life-cycle Guides (MELGs) have been developed as part of a collaborative research programme to assess and predict the environmental impacts of mining operations for New Zealand’s geology and environmental conditions. Email Dave
Cavanagh, J., Pope, J., Simcock, R., Harding, J., Trumm, D., Craw, D., Weber, P., Webster-Brown, J., Eppink, F. & Simon, K. (2018). Mine Environment Life-cycle Guide: mesothermal (orogenic) gold mines. 159 pgs. Christchurch: CMER.
What it's about:
The Mine Environmental Life-cycle Guides (MELGs) have been developed as part of a collaborative research programme to assess and predict the environmental impacts of mining operations for New Zealand’s geology and environmental conditions. Email Dave
Pope, J., Cavanagh, J., Harding, J., Trumm, D., Craw, D., Simcock, R., Webster-Brown, J., Weber, P., Christenson, H. & Eppink, F. (2018). NZ minerals sector environmental research - tools to make better mines. AusIMM New Zealand Branch Conference: Tauranga, pp. 265-274.
What it's about:
Underpinning science for the New Zealand minerals sector that builds on international expertise and experience to ensure that New Zealand operates mines with world class environmental performance. Email Dave and Hana
Geochemistry
Kerr, G., Craw, D. & Pope, J. (2022). Dissolution rates of arsenic minerals in natural and mining environments, New Zealand. In: Pope, J., Wolkersdorfer, C., Rait, R., Trumm, D., Christenson, H. & Wolkersdorfer, K. (Eds.) IMWA 2022 – Reconnect (pp. 181–186). Christchurch, New Zealand: International Mine Water Association.
What it's about:
Mineral solubility is widely recognised as a control on environmental release of dissolved arsenic. Thermodynamic modelling indicates that most arsenic minerals are readily soluble when exposed to surface waters. However, field observations and actual measurements demonstrate that in some environments, these thermodynamically predicted solubilities are overestimated. This study compiles empirical observations made on several arsenic minerals across a range of sites in New Zealand. Email Dave
Fairgray, M., Webster-Brown, J. & Pope, J. (2020). Testing geochemical predictions of trace element toxicity and bioavailability at a rehabilitated mine site. Mine Water and the Environment, 39, 75–92. DOI: 10.1007/s10230-019-00644-y.
What it's about:
When Acid Mine Drainage (AMD) or treated AMD mixes with surface waters, secondary chemical reactions can occur. We tested the effectiveness of geochemical modelling to predict chemistry in environments downstream of a rehabilitated abandoned mine.
Jewiss, C., Craw, D., Pope, J., Christenson, H. & Trumm, D. (2020). Dilution processes of rainfall-enhanced acid mine drainage discharges from historic underground coal mines, New Zealand. Mine Water and the Environment, 39, 27-41. DOI: 10.1007/s10230-019-00650-0.
What it's about:
Rainfall induced chemical and flow changes to Acid Mine Drainage from abandoned underground mines can be out of phase with flushing and dilution in the surrounding catchments. We investigate these processes at abandoned mines on the west coast of New Zealand. Email Hana and Dave
Butler, S., Pope, J., Chaganti, S., Heath, D. & Weisener, C. (2019). Biogeochemical characterization of metal behavior from novel mussel shell bioreactor sludge residues. Geosciences, 9, 1, 50. DOI: 10.3390/geosciences9010050.
What it's about:
To understand associated risks related to storage or use of the Acid Mine Drainage sludge material, a laboratory mesocosm study investigated the physio-chemical and biological influence in two conditions: anoxic storage (burial deep within a waste rock dump) or exposure to oxic environments (use of sludge on the surface of the mine).
Christenson, H., Pope, J., Trumm, D., Newman, N., Rubio, I., Kerr, G., Young, M. & Uster, B. (2019). Manganese and trace element removal from New Zealand coal mine drainage using limestone leaching beds. New Zealand Journal of Geology and Geophysics, 62, 2, 1-12. DOI: 10.1080/00288306.2018.1540995
What it's about:
Limestone leaching beds are used in passive treatment systems to remove manganese - Mn(II) - from mine drainage. Email Hana, Nigel and Dave
Uster, B., Milke, M., Webster-Brown, J., O'Sullivan, A., Pope, J. & Trumm, D. (2019). Effect of alkalinity source on mechanisms of iron, manganese and zinc removal from acid mine drainage by sulfate-reducing bioreactors. engrXiv, 3 December 2019. DOI:10.31224/osf.io/yzh9s.
What it's about:
We investigated the effect of two different sources of alkalinity on metal removal in sulfate-reducing bioreactors. Four upward-flow sulfate-reducing bioreactors containing a mixture of organic waste materials and either waste mussel shells or limestone as an alkaline amendment were tested. Email Dave
Christenson, H., Pope, J., Craw, D., Johns, J., Newman, N. & Trumm, D. (2018). Characterisation of arsenic geochemistry in mine tailings from a mesothermal gold deposit. In Wolkersdorfer, C., Sartz, L., Weber, A., Burgess, J. & Tremblay, G. (Eds.), Risk to Opportunity, Vol 2, (pp. 573-578). 11th ICARD | IMWA | MWD Conference. Pretoria, South Africa: ICARD.
What it's about:
Geochemical modelling and determining (As) concentrations in pore water of a mine tailings facility. Email Hana, Nigel and Dave
Fairgray, M., Pope, J., Trumm, D. & Webster-Brown, J. (2018). Water chemistry changes in Cannel Creek following remedial work of Bellvue Mine AMD. AusIMM New Zealand Branch Annual Meeting: Tauranga, pp. 361-362.
What it's about:
Monitoring of water quality to determine if treatment of the Acid Mine Drainage (AMD) is working as expected and whether the stream water quality has improved. Email Dave
Kerr, G., Craw, D., Trumm, D. & Pope, J. (2018). Authigenic realgar and gold in dynamic redox gradients developed on historic mine wastes, New Zealand. Applied Geochemistry, 97, 123-133. DOI: 10.1016/j.apgeochem.2018.08.009
What it's about:
Realgar and gold precipitation processes usually occur at > 100 in geothermal systems – we identified these geochemical processes at ambient temperature in historic mine waste. Email Dave
Pope, J., Christenson, H., Gordon, K., Newman, N. & Trumm, D. (2018). Decrease in acid mine drainage release rate from mine pit walls in Brunner Coal Measures. New Zealand Journal of Geology and Geophysics, 61, 2, 195-206. DOI: 10.1080/00288306.2018.1448289
What it's about:
One of only a few peer reviewed publications globally that provides a basis for prediction of the longevity of mining related impacts on water quality. Email Hana, Kerry, Nigel and Dave
Treatment and rehabilitation
Christenson, H. K., Skews, R., Trumm, D., Pope, J., Newman, N., Lee, G., Ross, D. & Boyt, C. (2022). Enhanced passive treatment of sulfate and nitrate enriched mine water: Laboratory optimisation experiments. In: Pope, J., Wolkersdorfer, C., Rait, R., Trumm, D., Christenson, H. & Wolkersdorfer, K. (Eds.) IMWA 2022 – Reconnect (pp. 47–52). Christchurch, New Zealand: International Mine Water Association.
What it's about:
Enhanced passive treatment systems (EPTS) are bioreactors dosed with nutrients to improve water treatment rates relative to traditional passive treatment systems.This paper presents laboratory trials of enhanced passive treatment systems to treat waste rock stack seep water from Macreas Mine. Email Hana
Craw, D., Rufaut, C., Pillai, D. & Kerr, G. (2022). Rehabilitation of extreme chemical substrates on mine sites without soil in a semiarid climate, New Zealand. In: Pope, J., Wolkersdorfer, C., Rait, R., Trumm, D., Christenson, H. & Wolkersdorfer, K. (Eds.) IMWA 2022 – Reconnect (pp. 59–64). Christchurch, New Zealand: International Mine Water Association.
What it's about:
Observations from six historical placer gold mines in southern New Zealand have shown that soil-free impermeable clay-rich substrates develop evaporative salt encrustations. Endemic halophytic plants can tolerate these extreme conditions, and enhance local biodiversity. Part of this research project has been a two-year pilot study to physically remove areas of encroaching sediment and weeds to expand the bare substrates and facilitate halophyte colonisation. This approach is a viable option for enhancing biodiversity on mine sites with extreme chemical environments. Email Dave
Hayton, S., Trumm, D., Horton, T., Pope, J., Ross, D. & Williams, M. (2022). Passive treatment for elevated iron and arsenic in circum-neutral mine affected water. In: Pope, J., Wolkersdorfer, C., Rait, R., Trumm, D., Christenson, H. & Wolkersdorfer, K. (Eds.) IMWA 2022 – Reconnect (pp. 147–152). Christchurch, New Zealand: International Mine Water Association.
What it's about:
Field trials were established at OceanaGold’s Globe Progress Mine, located in the West Coast of New Zealand, to determine the most appropriate passive treatment system for post-closure. The trials consisted of four bioreactors, with the addition of biosolids or mussel shells, to treat combined underdrain seepage. A vertical flow reactor (VFR), which utilizes oxidation of iron-rich water to co-precipitate and adsorb metals onto a non-reactive gravel bed, was also trialled to treat a separate underdrain seepage. Email Dave
Trumm, D., Moynihan, E., Young, J. & Pope, J. (2022). Passive treatment of AMD using a full-scale upflow mussel shell reactor, Echo Coal Mine, New Zealand. In: Pope, J., Wolkersdorfer, C., Rait, R., Trumm, D., Christenson, H. & Wolkersdorfer, K. (Eds.) IMWA 2022 – Reconnect (pp. 511–516). Christchurch, New Zealand: International Mine Water Association.
What it's about:
This work presents the results of the first full-scale up-flow mussel shell reactor at an active mine to treat AMD reported in the literature. In an up-flow configuration, the theory suggests that reducing conditions would be prevalent throughout the reactor, resulting in sulfate reduction and formation of sulfides rather than hydroxides which can reduce permeability with time in downflow reactors. Email Dave
Eppink, F., Trumm, D., Weber, P., Olds, W., Pope, J. & Cavanagh, J. (2020). Economic performance of active and passive AMD treatment systems under uncertainty: Case studies from the Brunner Coal Measures in New Zealand. Mine Water Environ, 39, 785–796. DOI: 10.1007/s10230-020-00710-w
What it's about:
Geochemists team up with an economist to identify bounding chemical and economic conditions that determine the applicability of passive and active mine water treatment options. Email Dave
Christenson, H., Weber, P., Pope, J., Newman, N., Olds, W. & Trumm, D. (2018). Enhanced passive treatment systems: addition of nutrients to bioreactors. AusIMM New Zealand Branch Annual Meeting: Tauranga, pp. 97-104.
What it's about:
This research presents results of adding water soluble nutrients to traditional bioreactors targeting sulfate and nitrate removal from water. Nutrient addition led to a more than 15-fold improvement to the amount of sulfate removed from mine water relative to the control. Email Hana, Nigel and Dave
Forbes, E., Trumm, D., Pope, J. & Bell, D. (2018). Comparison of diversion well substrates for the treatment of acid mine drainage Bellvue Mine, West Coast, New Zealand. In Wolkersdorfer, C., Sartz, L., Weber, A., Burgess, J. & Tremblay, G. (Eds.), Risk to Opportunity, Vol 2, (pp. 116-120). 11th ICARD | IMWA | MWD Conference. Pretoria, South Africa: ICARD
What it's about:
This research aimed to test the efficiency of a diversion well using mussel shells in treating acid mine drainage at Bellvue, an abandoned coal mine north of Greymouth, in comparison to the more traditional diversion well using limestone. Email Dave
Hillman, C.P., Trumm, D., Bello-Mendoza, R. & Pope, J. (2018). Quantifying and treating contaminant discharges from the James Mine on New Zealand's West Coast. AusIMM New Zealand Branch Conference: Tauranga, pp. 373-374.
What it's about:
Using laboratory research and field experiments, this research sought to identify and test an effective method to treat the effluent from James Mine, a legacy coal mine with acid mine drainage with high acidity and metal loads, at its source. Email Dave
Trumm, D., Christenson, H., Pope, J., Watson, K., Mason, K., Squire, R., McDonald, G. & Mazzetti, A. (2018). Treatment of high Mn concentrations at Wahia Gold Mine, New Zealand by two methods: A limestone leaching bed and a slag leaching bed. In Wolkersdorfer, C., Sartz, L., Weber, A., Burgess, J. & Tremblay, G. (Eds.), Risk to Opportunity, Vol 1, (pp. 204-209). 11th ICARD | IMWA | MWD Conference. Pretoria, South Africa: ICARD.
What it's about:
This research trialled passive treatment systems at sites with high Mn concentrations. Two parallel systems were trialled: one with a slag leaching bed and the other with a limestone leaching bed. Email Hana and Dave
Trumm, D. & Pope, J. (2015). Passive treatment of neutral mine drainage at a metal mine in New Zealand using an oxidizing system and slag leaching bed. Mine Water Research in New Zealand, 34, 4, 430-441. DOI: 10.1007/s10230-015-0355-3
What it's about:
A pilot-scale passive treatment system that included an oxygenation cascade of drops through V-notch weirs, settling ponds, and a slag leaching bed was found to be effective for removing iron (Fe), manganese (Mn), zinc (Zn), and arsenic (As) from mine waste run-off. Email Dave