Tuesday, May 6, 2014

How much ammonia does a penguin emit?

A study conducted by researchers at the UPM and in the UK has estimated the ammonia rate that a penguin colony emits in the atmosphere and its direct effects on the ecosystem.
The researcher Mark Theobald, from the research group of Pollution of Agricultural Systems by Agricultural Practices of the Universidad Politécnica de Madrid (UPM), has conducted a study in collaboration with UK scientists about a colony of 39,000 Adélie penguins from Antarctica. The results obtained show that penguins emit 43 kg of ammonia every day which is a similar rate to the emissions of a poultry farm with half a million birds.

Penguins, like all living beings, emit ammonia in the atmosphere. In the case of penguins, part of the ingested nitrogen from eating fish is emitted in the air in form of ammonia (NH3). In fact, large penguin colonies can emit more NH3 than massive livestock farms, but with the difference that the first group lives in less altered pristine ecosystems. This situation allows researchers to analyze the physicochemical processes of NH3 emissions and their ulterior spreading in near ecosystems. All this is studied in an onsite lab.

The NH3 that travels in the air stream from penguin colonies to sensitive ecosystems leaves behind an excess of nitrogen. It would be something similar to adding fertilizers to these ecosystems which could cause irreparable damage. In the case of penguins, this problem is related to a natural situation, but it is quite similar to factory farms that emit NH3 close to sensitive ecosystems.

The first thing to understand the mentioned physicochemical processes is to measure the NH3 produced by penguins. Researchers have indeed measured the NH3 concentration in several areas around the colony in order to estimate later the amount of NH3 emitted by animals using dispersion models that simulate air movements in the atmosphere. These types of models are usually used to predict impacts of air pollution through gas flow simulation or particles from a resource to a receiver (person or ecosystem). However, the same models can predict emissions from a data concentration measured at a particular location (inverse modeling).

By using this methodology, scientists were able to estimate that a penguin colony releases 43 kg of NH3 in the atmosphere every day, which is a similar figure to the emissions produced by half a million chickens in a massive livestock farm.

To know the amount of NH3 produced by the penguin colonies, the first step is to study what amount of NH3 released by these animals can begin to affect nearby ecosystems. This study will also allow researchers to learn about the response of these sensitive systems to air pollution, such as the contamination directly associated to NH3 emissions.

THEOBALD, MR; CRITTENDEN, PD; TANG, YS; SUTTON, MA. “The application of inverse-dispersion and gradient methods to estimate ammonia emissions from a penguin colony”. Atmospheric Environment 81: 320-329. DOI: 10.1016/j.atmosenv.2013.09.009. December 2013.


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