Midsummer weekend, students set up their “at home” Winogradsky column experiments which ended 5 weeks later in July. Winogradsky columns are designed for observing the succession of microbial populations.

Dr. Rachel Foster, co-course leader, used the Winogradsky column exercise for the first time this year, and felt it was a success. She noted, that:

"The students seemed genuinely engaged and enthusiastic while reporting to the group the results. Several even asked if they could continue their experiments".

The columns are clear and filled with sediments, supplemented with nutrients, and left to sit and develop. The columns change color as certain bacterial populations are enriched.

Here, the marine biology students designed their own experiments, worked in teams of 3-4 students collecting sediments in the Stockholm area. Supplements included adding carbon (newspaper, sugar), sulfur (egg), combinations of carbon and sulfur, or none at all (control). Some students experimented with adding pond and oceanic water. Others tested the influence of temperature and light. Students observed changes in their experiments as the course progressed through summer.

One team hypothesized that urban areas (Söder, Östermalm) would result in poor growth due to anthropogenic disturbance compared to sediments collected from rural areas.

Forest clearing in the rural area Nybodahöjden Stockholm where the experimental sediments were taken.
A rural area - a park in Östermalm where the experimental sediments were taken.

However, observations were similar in both the urban and rural sediment columns. Surprisingly grass started to grow in the rural experiment.

Column from a rural area in the end of the experiment.
Columns from the urban area in the end of the experiment.