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Story: Superphosphate

Guano

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Guano

Guano is the accumulated dried droppings from sea birds, bats and seals. It is naturally high in phosphorus and nitrates. However, in high rainfall areas the nitrates are leached from the material. When mined it is referred to as rock phosphate. Nauru Island, north of the Soloman Islands, was the early source of rock phosphate for superphosphate manufacture in New Zealand. This supply is now exhausted and other sources are used. This mine site is on one of the Ballestas Islands, off the coast of Peru.

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by David Haynes

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How to cite this page

Arthur Duncan, Superphosphate – New Zealand superphosphate, Te Ara – the Encyclopedia of New Zealand, https://teara.govt.nz/en/photograph/15570/guano (accessed 4 June 2026).

Story by Arthur Duncan, published 1 March 2009.