For the first time in several years, Oceana commissioned a report by KPMG to analyse its contribution to local economies, benefits from taxes and royalties and its environmental management.
In 2015 12.6 tonnes of gold was mined across New Zealand, the vast majority by Oceana, which by 2016 accounted for about 98% of production, at the time valued at $639.4 million.
As at June 2016, gold was the second-largest export to Australia, behind crude oil, and for the full year represented 1.1% of the country's total commodity exports.
While gold is historically linked to coin and jewellery manufacturing, its properties are seeing it increasingly used in new technologies, ranging from telco devices, appliances and pharmaceutical products through to gold nanoparticles used in cancer treatments.
''They [nanoparticles] are also used to create more efficient solar energy and specially designed chemical catalysts which help break down contaminants in groundwater,'' the report said.
KPMG said to best understand Oceana's economic contribution, it had focused on expenditure into economies, contribution to gross domestic product (GDP) and export revenue.
Oceana's largest economic contribution during 2016 was a total $305 million paid to suppliers and contractors, of which $239 million, or 78% of the total spend, went to New Zealand businesses.
During 2016, Oceana employed 894 people, across Otago and Waihi and also Reefton on the West Coast, although Reefton has since been shut down and the site is being rehabilitated.
The average earnings per employee was $102,945, almost double the mean earnings of an employee in New Zealand of $52,800
''Through these salaries and wages, Oceana Gold makes a significant and positive contribution to supporting the livelihoods and economic participation of employees within their local and regional communities,'' the study said
Oceana's proportional regional contribution to Otago's GDP was 0.88%, or almost $84 million and in the Waikato 0.44%, or $86 million.
During 2016, Oceana employed 534 full-time equivalents staff at Macraes, or about 4.5% of the Waitaki district's employees and 351 at Waihi, or 4.4% of the Hauraki district.
''Total wages and benefits for the Macraes mine were $53 million on site and $4.5 million at the Dunedin head office,'' the study said.
During 2016, Oceana set aside $4.9 million for environmental management, which was used for water management and revegetation around Waihi, rehabilitation at Reefton and for registering perpetuity covenants over 267ha at Macraes.
''The four covenants cover a range of flora values with sub-montane alpine tussock grasslands, scrubland, shrub land and wetland ecosystems being protected and enhanced,'' the report said.
Two more covenants have been proposed for Macraes, covering 390ha, and are expected to be registered this year.
At Reefton, Oceana wanted to ultimately return the land to its natural forested state and had allocated $50,000 per ha for rehabilitation, to a total of $16 million. At Waihi it wants to gradually transfer mining land back into grazing land.
Oceana's investment in local communities contributed $945,000 for the year, which around Macraes included $150,000, over two years, for a new medical centre in Palmerston, more than $100,000 to local schools and educational trusts and more than $126,000 to community and sporting clubs, including sponsorship of Otago rugby.
''The company has made a significant contribution to fostering New Zealand's gold mining heritage and history at both Macraes and Waihi sites, through preservation, community education and encouraging mine-related tourism,'' the report said.