Albert Fuller Ellis's discovery of extensive phosphate deposits on Nauru and Ocean Island was to transform agriculture in New Zealand and Australia. He was born in Roma, Queensland, on 28 August 1869, the third son of George Coxon Ellis, a chemist, and his wife, Anne Eliza Izod. The family moved in October 1869 to New Zealand, where George Ellis became a farmer in the Waikato district. Albert was educated at Cambridge, attending the district high school in 1884 and 1885. At the age of 18 he joined his father and his brothers James and George in working for John T. Arundel and Company of London, which had widespread trading interests in the Pacific islands. It also invested in plantation development and prospected for the guano that could be found on many of the low-lying coral islands of the central Pacific.
Ellis spent some three years in the Phoenix Islands. He planted coconuts on Hull and helped to manage the phosphate workings on Baker and Howland Islands where he supervised a workforce of nearly 100 men and tested samples in the rudimentary laboratory. In 1890, most of the known guano deposits in the Pacific islands having been worked out, the company turned its attention to the north Queensland coast. Ellis was involved with mining operations at Raine and Lady Elliott Islands and with prospecting on the Bunker and Capricorn groups.
In 1899 Ellis was transferred temporarily to Sydney as the company's analyst. Soon after his arrival he conducted chemical tests on a curious rock used as a doorstop in the office of the Pacific Islands Company, as the restructured Arundel company was now called. The rock, thought to be fossilised wood, had been brought back from German-administered Nauru some years before. Ellis thought it looked more like rock phosphate – a hunch confirmed by his analysis.
In March 1900 Ellis sailed for the central Pacific with his wife, Florence Christina Stewart, whom he had married at Auckland on 31 January. She soon returned to Sydney because of ill health, and her pregnancy was to end in miscarriage. Ellis's cursory examination of Ocean Island (Banaba), a raised atoll close to Nauru, confirmed enormous deposits of alluvial and rock phosphate based not on guano but ancient marine sedimentation. Ellis conducted negotiations with the leaders of Ocean Island's Banaban people, while the Pacific Islands Company exploited its imperial connections to secure a mining licence and British annexation for the island; it also won a mining concession at Nauru. Ellis's agreement with the Banabans – that the company pay £50 a year in return for the exclusive right to mine for 999 years – was harshly criticised when it became known; it was later modified to provide royalties and compensation for mining damage.
Ellis became the mining manager for the company, renamed the Pacific Phosphate Company in 1902, and oversaw operations at Nauru when mining began there in 1906. He lived on Ocean Island with Florence and their daughter, Joan. By 1911 he had tired of the pioneering life; Florence Ellis had died in 1909 and, now that the company was manufacturing superphosphate as well as mining, Ellis may have lacked the financial and engineering skills the position had come to demand. He took up the new Auckland-based position of local director for Australia, New Zealand and the Pacific islands. On 19 February 1913 at Auckland he married Nellie Isabel Stewart, Florence's sister; they had no children.
Following the First World War Nauru was passed as a League of Nations mandate to Britain, Australia and New Zealand, with Australia as administering power. The three governments established the British Phosphate Commissioners to run the industry, and Ellis was appointed phosphate commissioner for New Zealand in May 1920, a position he held until his death. He had little real power or influence, although he contributed to the policy making of the commission and its liaison with the New Zealand government.
Ellis became a great publicist for the phosphate and fertiliser industries, contributing frequently to the New Zealand Journal of Agriculture and similar publications. He also wrote Ocean Island and Nauru: their story (1935); Adventuring in coral seas (1936), on his early life; and Mid-Pacific outposts (1946), which dealt with the Second World War in the central Pacific. In 1945 he represented the New Zealand government at the Japanese surrender ceremonies on Ocean Island and Nauru. For his contribution to the phosphate industry and New Zealand agriculture Ellis was appointed a CMG in 1928 and was knighted in 1938.
Albert Ellis combined a creative and adventurous spirit with a modest and dignified demeanour. He was for many years an elder of the Presbyterian church, a Bible class leader, a director of the New Zealand Bible Training Institute, and a council member (and honorary treasurer) of the Scripture Union. He was a founder member of the Rotary Club of Auckland in 1921 and became a fellow of the Royal Geographical Society, London, in 1927. He died in Auckland on 11 July 1951, survived by his daughter and his second wife.