Theses

We always welcome students for Bachelor and  Master theses. Topics for theses include experimental work in the lab, field work, as well as analyses of established data sets. Note that specific topics may determine the start time of the thesis (some theses with field work can only be done during the summer season).

Influence of climate variability and oligotrophication on winter survival of juvenile perch

How do oligotrophication and climate warming (mild winters) affect  the survival and condition of juvenile perch in Lake Constance.  Do perch get smaller? Does their fat content decline? Is there a higher risk for smaller individuals to not survive winter?  To answer these questions, the candidate will analyse a data set of lengths and fat contents of juvenile perch caught at the onset of winter (November) and the end of winter (April) in each winter from 1999/2000 until 2015/2016.

Preferred start of thesis: anytime

Comparative analyses of zooplankton seasonal succession in Upper and Lower Lake Constance using automated plankton imaging

Analyses of zooplankton communities is a very labor-intensive and time-consuming process. Automated plankton imaging and species identification offers a promising way to speed up zooplankton analyses thereby allowing studying zooplankton dynamics with a higher temporal resolution and/or comparative studies involving many lakes. The zooscan is such an imaging tool and the student will train the software to identify zooplankton species from Upper and Lower Lake Constance, identify and measure zooplankton from sample of one season, and compare zooplankton seasonality and size structure in the two lake basins.

Preferred start of thesis: anytime

Upper thermal limits of zooplankton

Climate change might result in increasing stress of zooplankton populations. The ability of zooplankton to withstand effects of climate warming might be related to their physiological upper thermal limits. Upper thermal limits of zooplankton in turn can be determined via measuring the time to immobilization for zooplankton at 37°C. In this thesis the student will measure and compare time to immobilization for differently sized individuals from different zooplankton species from Lake Constance, and its dependence on acclimatization.

Preferred start of thesis: anytime

Kairomone-induced morphological changes in different cladoceran species

The cladocerans Bythotrephes longimanus and Leptodora kindtii are important predators of several herbivorous cladocerans in Lake Constance.  Their kairomones are known to induce life history changes and morphological changes in Daphnia. In this thesis the candidate will study whether smaller cladoceran species such as Bosmina and Diaphanosoma will also be affected by the kairomones of the two predators.

Preferred start of thesis: June/July

Spatial variability of macrophyte-associated invertebrates

In this thesis macrophyte-associated macroinvertebrates from various sites in Upper and Lower Lake Constance will be sampled in summer. The candidate will examine the community structure and species diversity of invertebrates on various macrophyte patches and analyse the role of spatial distance for community differentiation. 

 Preferred start of thesis: June