One case is related of the Hon. Jamei PeaTce, who first applied guano in 1845, at th( r?e of 550 lbs. to the acre of very poor land It was applied as a top dressing mixed wit! plaster, for a crop ...

Humboldt penguin populations have been reduced by guano mining, which destroyed their nesting sites; the fish they eat being taken by commercial fishing; and harsh seasons of El Niño.