Ona was at one time employed by Bougainville Copper at the mine, but he became increasingly critical of its operations' adverse effect on the environment and what he claimed was the low level of royalties paid the landowners. Most of the profits left Bougainville Island, but its society was disrupted by thousands of workers from Papua New Guinea, as well as Australians. From the mid-1980s, Ona and others challenged the leadership of the Panguna Landowners Association (PLA), claiming that they were not representing the interests of all the traditional landowners.