tax, but also between miners and settlers over conflicting land use. Attention turned to the gravel beds of the Clutha River, with a number of attempts to develop a steam-powered mechanical gold dredge. These finally met with success in 1881 when the Dunedin became the world's first commercially successful gold dredge. The Dunedin continued operation until 1901, recovering a total of 17,000 ounces (530 kg) of gold. The mining has had a considerable environmental impact. In 1920 the Rivers Commission estimated that 300 million cubic yards of material had been moved by mining activity in the Clutha river catchment. At that time an estimated 40 million cubic yards had been washed out to sea with a further 60 million in the river. (The remainder was still on riverbanks). This had resulted in measured aggradation of the river bottom of as much as 5 metres. Gold is still mined by OceanaGold in commercial quantities in Otago at one site - Macraes Mine inland from Palmerston, which started operations in 1990. Macraes Mine, an opencast hard rock mining operation, processes more than 5 million tonnes of ore per year and from 1990 through 2014, gold production has totaled about 4 million ounces. The Otago gold rush in popular culture Numerous folk songs, both contemporary and more recent, have been written about the gold rush. Of contemporary songs, "Bright Fine Gold", with its chorus of "Wangapeka, Tuapeka, bright fine gold" (sometimes rendered "One-a-pecker, two-a-pecker") is perhaps the best known. Most well-known of more recent songs is Phil Garland's song Tuapeka Gold. Martin Curtis wrote a folk-style song about the gold rush called "Gin and Raspberry." The lyrics are written in the voice of an unsuccessful gold prospector who envies the success of the largest gold mine in the Cardrona valley at the time, the "Gin and Raspberry" (supposedly so named because the owner would call out, "Gin and raspberry to all hands!" whenever a bucket of mined material yielded an ounce of gold. The singer laments, "an ounce to the bucket and we'd all sell our souls/For a taste of the gin and raspberry." The song has had several recordings, particularly by Gordon Bok. Paul Metsers' song "Farewell to the Gold" is based loosely on a flood in July 1863, which killed 13 miners on the Shotover River. The song has been recorded by many, including Nic Jones, The Black Family, James Keelaghan,