Stratification

As we have learned, phytoplankton need sunlight, carbon dioxide and nutrients to grow so they must be living near the surface of water. But how can climate change decrease plankton productivity? Well, the answer is simple! As we emit more greenhouse gases, we are rising the Earth's temperature. The ocean are being stratified into warm and cold layers, causing the nutrients to sink deeper to the bottom of the ocean. The required nutrients will become limited for the phytoplankton because they can't live without sunlight. 
          The effect global warming and stratification
But where do these nutrients come from? Most nutrients are in the soil and brought into the ocean by rain. Other source is from decaying animals at the bottom of the ocean. 

 Some mechanisms that help bring nutrients up towards the surface are wind and wave. Typically, wind and wave will do the job of mixing the cold and water layers but when the surface water gets too warm that will no longer be possible. This is because cold water is more dense than the warm water and every time they try to mix, the cold layer along with the nutrients will quickly sinks back down, which makes it impossible for the phytoplankton to obtain enough nutrients.

2 comments:

  1. UnknownNovember 12, 2012 at 5:21 PM

    I like your foundation i.e. your work is well detailed and explanatory. Some things to review include making your statement clear throughout each tabs; for instance, in the 4th sentence of this tab, a correct version to your words could be "...the ocean are being stratified into warm and cold layers causing nutrients to sink deeper to the bottom of the ocean".Also include some in-text citations. Overall you have done a Great Job!!

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  2. AnonymousNovember 13, 2012 at 2:57 PM

    Good explanation about how climate change affects phytoplankton. Your first two sentences should have read like this: "We learn [that] phytoplankton need sunlight, carbon dioxide and nutrients to grow so they must [live] at the surface of the water. But how could global warming contribute to the [decrease] in number of phytoplankton?" Changes in brackets. Your figure helpfully demonstrates what you are explaining in your text.

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