Independence Group Sustainability Report 2019

UNDERSTANDING THE HEALTH OF OUR TOPSOIL The effectiveness of mine site rehabilitation is dependent on the quantity and quality of the topsoil available to be placed onto post-mining land forms. This soil is typically sourced during the pre-mining activities when it is stripped from mining areas and stockpiled for later use. While it is common to have enough topsoil at the end of mine life for rehabilitation works, the quality is often poor. As any good gardener will tell you, soil is so much more than its insoluble mineral constituents. Good soils are high in organic matter, nutrients, seed and critically, soil microbes. A variety of factors affect the quality of stored topsoil, including the size and depth of stockpiles, duration of storage, soil type, climate and method of storage. In January 2019, IGO commenced participation in a study led by Dr Haylee D’Agui with the ARC Centre for Mine Site Restoration (CMSR) from Curtin University. The aim of this research is to determine how the diversity, abundance and activity of soil microbes within topsoil stockpiles is influenced by factors such as storage time. The Nova Operation is one of seven mines that will contribute data to inform the development of topsoil management guidelines that will improve mine site restoration outcomes. Keith Ashby, IGO’s Head of SHEQ and Risk highlights, “It is important that we support scientific research into the management of topsoils specifically, and in mine site rehabilitation generally. Doing this well will safeguard both IGO’s future licence to operate and contribute to that of the industry.” ADDRESSING THE FERAL CAT PROBLEM Mining-related activities in remote Australia can unfortunately support elevated populations of feral cats. Predation by cats have contributed to the extinction of many small Australian animals and they continue to pose a material threat to many of our remaining small wildlife. A recent scientific analysis of the diet of feral cats recorded 400 native and non-native vertebrate species that feral cats feed on or kill in Australia. These included 17 EPBC Act–listed species, 123 birds, 157 reptiles, 58 marsupials, 27 rodents, 5 bats, 21 frogs, and 9 medium-sized and large exotic mammals. Cats also consume a wide range of insects, spiders, scorpions, centipedes and crustaceans. Given this, IGO saw an opportunity to contribute to the efforts in addressing the problem. Managing feral cat populations is notoriously difficult. Current techniques include trapping and baiting, but neither are particularly successful because cats rarely scavenge baits. The development of an automated device to control cats without requiring them to be attracted to baits is a key requirement of the Australian Government’s threat abatement plan for predation by feral cats. One such device is known as the Felixer. With the support of mining companies including IGO, government agencies and non-government organisations, the Felixer has evolved over three generations of prototypes. This has culminated in the trial of 56 units of the device over the past 18 months. The sensor and controlling algorithms detect and discriminate the target as a cat, prior to firing a blob of toxic gel that adheres to the cat’s fur. As cats are fastidious groomers, they ingest the gel and perish due to the ingestion of the poison. To date the trials have proven successful. The photo shows the gel on a cat at the timing of the Felixer activation. Work is ongoing to commercialise the manufacture of Felixer by not-for-profit company Thylation. IGO looks forward to playing its part in the ongoing development of the technology. For more information refer to Thylation’s website at www.thylation.com . IGO SUSTAINABILITY REPORT 2019 — 41