Tuesday, March 6, 2012

Dust


You never really think of dust as having a huge impact on the large ocean. The strong winds go over the Sahara desert and they pick up fine dust particles. The dust is composed of soil particles. These dust particles come down and settle on the surface of the ocean. The particles are referred to as “Desert dust.” The desert dust has been found to be rich in nutrients. The iron in the dust helps the growth of the phytoplankton in the ocean. 
The research on desert dust was done by the Royal Research Ship Discovery in the North Atlantic Ocean. The dust can limit the amount of radiation that reaches the Earths’ surface. This can in turn affect the clouds and precipitation.  Researchers wanted to find out what the impact of the desert dust had on the metabolism of the oceanic bacteria. There were visible dust clouds during the voyage. The samples were taken from depths of 20 meters. The studied was narrowed down to look at two bacteria. They are Prochlorococcus and SAR11 bacteria. The prochlorococcus is known to be the main producer of carbon dioxide fixation in the ocean.  The SAR11 bacteria are known to respire organic carbon and it releases carbon dioxide.
It was found that the desert dust has the potential to change the composition of the bacterioplankton community in the sub-tropical North Atlantic Ocean. The studied concluded that the SAR11 benefitted the most form the desert dust. The increase growth of the SAR11 out competed the prochlorococcus. There are still other studies to understand more of what the effects of the desert dust has on the phytoplankton growth.

5 comments:

  1. In this study and research done did they find that the desert dust was more of a hazard and negative to the ocean with phytoplankton and carbon dioxide? Or has the dust that was picked up from the desert been more of a help to the ocean? It is definitely and interesting study that has been carried out. I would have never guessed that the dust can build up on the water's surface, but it does make sense.

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    1. The phytoplankton would be positively affected by the dust if the dust has high amounts of iron in it. The results suggest that there was more growth of the bacteria SAR 11. The results showed that if there are large amounts of SAR11 then there is a large depletion of the oxygen in the water. Looking at the entire scale of the ocean the dust does not harm the ocean; it just has the potential to change the bacterial composition of the bacterioplankton community over time.

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  2. My question to you is, does the dust ONLY come from the Sahara? Perhaps if it come from other sources then it could be a positive or negative source for the oceans.

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    1. In the sources that I had looked into they all link back to the Sahara. They did not find that the dust had a negative impact on the ocean in the study above. But, I did find that desert dust can be linked to red tides. These can have a negative impact on the ocean.

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  3. Wow this is so true! I never really have thought about how dust could affect the ocean. It just seems so insignificant. This really makes you think about all of the small, tiny details of this world that can have the greatest of effects!

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