back to human activities data
go to Guano Birds Data
Native populations of pre-Spanish Latin America used guano, or bird droppings, as a fertilizer to increase crop yield for centuries. Europeans came upon their use and value in the 19th century, and introduced it into world trade. Soon guano became a prized commodity, and was single-handedly responsible for boosting Peru's economy in 1830 to late 1870s.

At its peak between 1848 to 1875, Peru excavated over 20 million tons of guano for export to Europe and the United States, generating around $2 billion in profits. But by 1909-10, the guano reserve was so depleted it only yielded 48,000 tons. The Peruvian government established the Guano Administration Company to manage the guano reserves. The declining guano yield was coupled with declines in guano bird populations. By 1942, the Peruvian guano industry was no longer economically viable.

  1. What caused the guano supply to be depleted?
  2. How could the fall of the guano industry effect other Peruvian exports and industries?

MECHANISM

It is the droppings from the marine birds (Peruvian pelican, Peruvian booby, and Guano cormorant) on a series of islands off the coast of Peru that were thought to be most valuable and plentiful. These islands (Chinchas, the Ballestras, the Lobos, and the Macabi and Guanape Islands) are barren and rocky with no vegetation due to lack of rain in the area.

The minimal rain allowed the bird droppings to accumulate and bake. This prevented the valuable nitrates in those droppings from evaporating or washing away. Meanwhile, the ample anchovy supply off the Peruvian coast sustained a healthy population of guano birds (>15 million) who in turn produce droppings to be harvested.

  1. How do you think the growth of the anchovy industry effected the guano industry?
 
(www.american.edu/TED/GUANO.HTM; Thorp, 1978)
back to human activities data
glossary
 

This web site was created by Lynn Tran at the North Carolina State University, Department of Mathematics, Science, and Technology Education on 7/12/03. Faculty advisor Dr. David Eggleston, NCSU, Department of Marine, Earth, & Atmospheric Sciences. Last updated December 29, 2003 .