By: Kaila Ritchie
Carbon dioxide is one of the leading contributors towards the effects of global warming. The levels of this green house gas have been increasing since the industrialization period. Since then the amount of atmospheric carbon dioxide has increased 35%. The oceans are acting as carbon sinks absorbing about fifty times as much carbon dioxide. However Australian scientists have come to the conclusion that sperm whales are reducing the amount of atmospheric carbon dioxide in the oceans.
Previous studies have been made claiming that whales are a source of carbon dioxide. Although this is true, the amount of carbon dioxide that they remove is much greater. Trish J. Lavery and her team at Flinders University in Australia studied the southern sperm whales. The sperm whales produce feces with extremely high concentrations of iron which increases the amount of carbon dioxide removed. Adult sperm whales are large mammals that can weigh anywhere from 35 to 50 tons and consume approximately 200 tons of food per year. This much food intake means a lot of feces produced. The southern whales that were studied produced about 50 tons of wastes annually, keeping in mind that this is only around 3% of the global whale population. With all these whales defecating throughout the oceans, mass amounts of feces are produced, removing large amounts of green house gases.
The whale poop itself is a liquid that contains one extremely beneficial ingredient, iron. It is the iron in the whales’ feces that is vital for removing carbon dioxide. The iron rich feces acts as a fantastic fertilizer for phytoplankton. The phytoplankton population can grow and continue to go through the process of photosynthesis, which is the absorption of carbon dioxide in process of making food and replacing it by releasing oxygen. This process is known as the sperm whale-phytoplankton cycle. Artificial phytoplankton fertilizers were compared with sperm whale feces but the natural fertilizer contains more beneficial substances and continues to have better results. In the southern ocean alone this cycle is responsible for the removal of about 400,000 tons of carbon dioxide per year. This relationship is crucial for regulation of the carbon dioxide levels.
The reason that sperm whales have this valuable quality is directly related to their diet. They feed heavily in the photic zone, which is in the depths of the ocean. Therefore this quality is not limited to just sperm whales. Although other animals can also have high iron concentrations in their feces, due to the size of these whales they eat and produce in much larger quantities.
However, whale populations are declining. Sperm whale populations have been reduced 85-90% in the southern oceans. Whale populations took their biggest hit during 1940-1970 when over 60% of the population was killed off as a result of the whaling industry. With the whale populations dropping the phytoplankton are not far behind. Also correlations have been made with the decreasing populations of plankton and the rising temperatures of the oceans.
Other than the whales making a difference there are other theories in effect to lower atmospheric carbon dioxide levels. One being carbon dioxide capture protects. This is when carbon dioxide emissions from fossil fuel-fired power plants is captured and then stored in a secure underground location. In this location these harmful gases are no longer able to interact with the atmosphere. Also carbon based fuels have increased in price to reduce consumption. Alternative energy sources are strongly recommended and are used more and more often. There are always small steps that everyone can do. For example walk or ride your bike into town, recycle, conserve energy in your everyday lifestyle, and be environmentally conscious with everything you do. Even sperm whales are a part of the movement against global warming. Although this is not a solution it is very encouraging to know that even whales are helping the fight against global warming.
Reference List:
Lavery, T.J, Roudnew, B., Gill, P., Seymour, J., Seuront, L., Johnson, G., Mitchell, J.G., and Smetacek, V. 2010. Iron defecation by sperm whales stimulates carbon export in the Southern Ocean. Royal Society Proceedings B, 277:3527-3531.
"Advances in CO2 capture and storage technology." CO2 capture project. N.p., 2009. Web. 9 Oct 2010. http://www.co2captureproject.org/index.html
"Plankton and krill levels rapidly decreasing." International seakeepers society. N.p., 2010. Web. 9 Oct 2010. http://www.seakeepers.org/featured-plankton.php
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