University of Thessaly, Department of Ichthyology and Aquatic Environment, Team 21, Papakonstantinou Angeliki & Paschou Maria, Day 12, Incubation: Light

In order to create our Winogradsky column we followed the procedure below:

1)  Sand sediment  was collected from the Anauros beach.

2) Mixed the sediment with enrichment materials (1 egg and pieces of newspaper).

3) The sediment was added in a plastic bottle and filled the 2/3 of the column.

4) After that we added sea water to the rest of the column.

5) The column was covered with transparent film.

We put the column near a window (which is bright enough) in relatively stable conditions. At the 1^st day (21/3/16- pic.1) we can see that there is a clear separation between the liquid phase (sea water) and the solid phase (sea sediment). The liquid phase was observed and had a considerable turbidity with a yellowish color.

pic.1

After 3 days (24/3/16-pic.2&3)the only thing that changed was the color of the upper layer of the sea water, which became slightly whiter.

pic.2

pic.3

At the 8^th day of the experiment (28/3/16- pic. 4&5), on the upper layer of the column we observed a yellow foam with a relative increase in the turbidity of the liquid phase and a characteristic odor. The sediment showed a relatively darker color change from the first day. These facts may indicate the use of nutrients from the materials that have been chosen for the Winogradsky column, which leads to the growth of microorganisms and particulate matter. The light yellow color may be due to decomposition of organic matter (egg) and the accumulation of by-products of metabolism. Finally, the odor may be an indication of existence of hydrogen sulfide in the column.

 

                      pic.4                                           pic.5

Today (12^th day-2/4/16) the surface of the column became whiter (pic.6) and the liquid phase has lost its yellow color (it has a rather grey color) and more particulate matter has settled above the sediment, (pic.7).

                       pic.6                                              pic.7              

We will inform you with further observations as soon as we see any noticeable changes in the column.