White Rocks and Uric Acid

December 27, 2009


Middle BrewsteCormorant Colony
: Rob Sheridan 
Summary Author: Rob Sheridan

Accumulated droppings of seabirds are very high in fixed nitrogen in the form of uric acid (C5H4N4O3). Over the short-term (months), this white crystalline material stains nesting sites, as seen in this photograph of a cormorant colony on Middle Brewster Island in the Boston Harbor Islands National Park.  Over the long-term (hundreds of years), this material (seabird guano) can massively accumulate and become a valuable resource.

Prior to development of the Haber process in the early 1900's for fixation of gaseous nitrogen from the atmosphere, seabird guano was the principal source of fixed nitrogen for manufacture of fertilizers and explosives. Wars were fought over this valuable resource. The implications of Fritz Haber's nitrogen fixation process were so enormous that he was awarded the Nobel Prize for his work in 1918. The Haber process remains the major source of the nitrogen used in the chemical industry today. Photo taken on May 21, 2009.