Bird droppings produce 3.8 million tons of nitrogen per year

Photo Source: National Geographic Creative/Alamy Stock Photo
Long before modern agriculture was born, humans relied on three things to get nitrogen into barren soil: lightning strikes, nitrogen-fixing bacteria, and natural fertilizers. Of these three methods, millions of seabirds, such as the nesting slugs pictured, produce nitrogen- and phosphorus-rich bird droppings that they have earned a reputation as "white gold".
, a new study has revealed just how rich this gold is. An unprecedented statistic shows that 894 million seabirds and chicks that are breeding produce about 591,000 tons of nitrogen per year. The researchers reported the
in the Journal of Science and Technology.
together with faeces from non-breeding seabirds, seabirds produce about 3.8 million tons of nitrogen a year - slightly more than the amount of nitrogen transferred to the land through all fisheries, and 75 percent of the nitrogen fixed by bacteria in lightning and rice fields. An independent calculation estimates that nesting birds and chicks also excrete 99,000 tons of phosphorus per year.
researchers say that because about 12 percent of the nitrogen and 22 percent of phosphorus can't really dissolve, the seabird habitat is a "hot spot" for nutrients, providing abundant nourishment for land and marine plants that live in the stream. This is particularly true in the waters surrounding Antarctica and its surrounding islands, where seabirds are usually larger and have longer breeding seasons than seabirds elsewhere. (Source: Xu Xu, China Science Daily)