Kristin Scharnweber

Congratulations to Robyn and Erik who successfully defended their Master’s theses!

Robyn´s thesis has the title “The effect of different browning agents on the fitness and survival of Daphnia magna”. Robyn picked up on the findings of decreased zooplankton abundances of the first KAWater mesocosm experiments in 2016 in treatments with HuminFeed and conducted standardized OECD toxicity tests on lab cultures of Daphnia. Her results show a clear reduction in offspring numbers when Daphnia is cultured in HuminFeed, highlighting that this browning agents should only be used with greatest caution in future browning-related experiments.

For his thesis “Effects of productivity and predation on zooplankton and emerging chironomids in a mesocosm experiment”, Erik has collected zooplankton and emerging Chironomidae from the mesocosm experiment conducted in summer 2017. Therefore, he did an excellent handcraft-job by building the emergence traps that we also could further use in the next season. In his thesis, he found interesting interactions between bottom-up and top-down effects where nutrients can mitigate the effects of predation pressure.

Another chapter of Marias’ thesis was published. Ecology and Evolution “Asymmetrical habitat coupling of an aquatic predator—The importance of individual specialization”.

The first mesocosm paper is out! Congrats Anna for your work and endurance during the review process!

We have ended the KAWater mesocosm experiments at Lake Erken! We had three exciting years of sampling, trying things and sometimes fail. Now we have accumulated a lot of samples, some of them processed and some of them still waiting to be analyzed. I am looking forward for the interesting things we will learn from these experiments, but we have finalized one big step and that is the actual sampling. Many, many hands have helped during these campaigns. Thank you so much to the great KAWater team! Without your work, sweat, patience and endurance, this project would not be possible!

For one week, me and my fabulous assistants Leonie and Holger went to Jämtland in Northern Sweden to catch minnows (Phoxinus phoxinus) in beautiful Lake Ånnsjön and its tributaries to look at divergence patterns between the fishes inhabiting the lake vs. stream habitats. It has been an exhausting but very successful week in an amazing landscape.