What Krill do for Others.

http://marinebio.org/upload/Leptonychotes-weddellii/1.jpg

Krill as Food for other Marine Species

As I have discussed already, many species depend upon the Antarctic krill as a food source.  This cute Weddell seal to the right is one of them.  Humans also have a use for Antarctic krill through the health supplements.  As climate change continues and the Antarctic krill is affected through the various processes that I mentioned, it could drive the krill to deeper waters, affecting carbon sequestration and animal feeding patterns. it will become more cost-effective for animals to dive deeper to get krill, leading to phenotypic plasticity with a species and possibly to adaptation as the animal species such as whales. seals, and penguins continue to chase after this 2-inch morsel (Croxall et. al., 1999, Diet, provisioning, and productivity responses).  Another important function krill perform is carbon sequestration. Carbon sequestration is the process of capturing atmospheric carbon dioxide and the long term storage of the gas. This process can store carbon for up to 1,000 years and it goes towards enriching the already nutrient rich ocean floor so when the current brings particles from the bottom to the top during the time of the phytoplankton blooms, they will have plenty of nutrients to draw upon and bloom successfully.  The way Antarctic krill perform carbon sequestration is through a called the biological pump.  The biological pump is the biological processes that transfers carbon from the ocean surface to the ocean interior and stores it.

Hans Grobe, 8 August 2006

Krill and Carbon Sequestration

The way Antarctic krill contribute to the biological pump is through two ways.  When krill eat, they are very messy eaters and often make spit balls from their phytoplankton prey consisting of millions of cells and "spit" them out. The spit balls are relatively heavy and sink to the bottom.  Antarctic krill also produce fecal strings that contain carbon and the glass shells of diatoms, and this matter also sinks to the bottom.  One krill is only roughly 2 inches long so offhand you wouldn't think this is a significant amount of carbon sequestration.  Then you think about how there are about 30,000 individuals per cubic meter of the ocean and realize that actually quite a bit of carbon is being transferred to the bottom of the ocean (Tarling and Johnson, 2006, Satiation gives krill that sinking feeling).  If Antarctic krill populations continue to decrease as they have over the last 30 years, their ability to sequester carbon will decrease as well, resulting in more carbon dioxide in the atmosphere due to evaporation and possibly higher levels of ocean acidification.   More research is needed in the field of Antarctic krill studies due to their importance for not just other animals, but for the planet as a whole.  So, c'mon, show the krill some respect.