In the aerobic area, the top of the column, seaweeds may have grown so that they could produce oxygen after doing photosynthesis with the light the column receive everyday (the column is next to a window). This fact could be an explication to the bubbles we see at the top.
In the middle of the column there is no remarkable change. Here you have some photos to see all these changes and to follow better the evolution of our column.
Irene, Raúl and Nieves
Hi,
ReplyDeleteThe black colour is due to precipitates of FeS being formed abiotically from the H2S produced by sulphate reducing bacteria (anaerobic bacteria that respire SO43- instead of O2 like us) and Fe2+ that exists in the sediment.
Let's see how the column develops in the future.