Welcome to the aquatic ecology research! We offer PhD, Master-, Bachelor-, and State Exam theses in a vibrant research group with a friendly atmosphere. If you are interested please contact us or the colleagues listed below. Also have a look at the german version of this page.
Topic: River restoration, river ecology
Description: In cooperation with international partners from IRSTEA in France, the effects of woody riparian buffer strips on biodiversity will be investigated. This will include (i) a literature review, (ii) an analysis of the general reach-scale effects as well as some clearly novel aspects: (iii) an analysis of the effects of the spatial arrangement of woody buffers (e.g. fragmentation) at larger river network scales and (iv) the potential function of woody buffers as migration corridors. The analysis will be based on exising biological data and include GIS and remote sensing work to quantitativly and qualitatively describe the woody buffers as well as multivariate statistics. Funding will be through a scholarship, for which the PhD student will apply for, strongly supported by us.
Methods/Data: Literature review, fieldwork, statistics, GIS
Starting: Summer 2017
Contact: J.Kail
Topic: River ecology
Description: Long-term studies recently found a dramatic decrease of the biomass of flying insects of about 70% within the last 25 years. This trend is also visible in floodplain habitats but interpretation of existing studies is difficult and more comparable studies on different insect orders are necessary and planned. In this thesis, the long-term changes in the community composition of the order of caddisflies in river floodplains of the nature reserve "Die Spey" (Krefeld, Meerbusch) within the last two decades will be investigated.
Methods/Data: Sorting and species determination, literature review
Starting: Not specified
Contact: A.Lorenz, thomas.hoerren(at)koleopterologie.de
Topic: River ecology
Description: Identifying the taxonomic level (species, genus, family) necessary to investigate the relationships between biological traits (e.g. feeding types, habitat and flow preferences) and environmental descriptors (e.g. substrate composition). Trait composition will be calculated using three taxalists to investigate if different taxonomic levels lead to comparable results or not.
Methods/Data: Statistics
Starting: Not specified
Contact: C.Feld
Topic: River ecology, river restoration
Description: The input of fine sediment is considered one of the main pressures affecting aquatic organisms and reason for water bodies failing good ecological status (besides diffuse pollution and hydromorphological alterations). The objective is to investigate the effect of fine sediment on macroinvertebrates in rivers of the Ruhr catchment and to identify indicator species.
Methods/Data: Fieldwork, labwork, statistics
Starting: Not specified
Contact: A. Lorenz, A. Gieswein
Topic: River ecology, river assessment
Description: Quantifying differences in the flow regime of near-natural and degraded river reaches using a set of different hydrological indices. Investigating the effect of alterations of the flow regime on river biota in comparison to other environmental variables and pressures.
Methods/Data: Statistics
Starting: Not specified
Contact: C. Feld
Topic: River ecology, river restoration
Description: Taking multiple samples of benthic invertebrates in a restored section below a reservoir (Sorpesee) that alters the temperature regime and comparing growth rates to a nearby river reach unaffected by water temperature changes.
Methods/Data: Fieldwork
Starting: Not specified
Contact: C. Feld
Topic: River ecology, ecotoxicology
Description: Literature review on the inut and effect of herbicides on different freshwater organism groups. After compiling the literature, either as a meta-analysis (quantitative) or a classical narrative review.
Methods/Data: Literature review
Starting: Not specified
Contact: C. Feld
Topic: River restoration
Description: Compiling information on the effect of restoration on river biota (literature review, analyzing existing databases, fieldwork). Developing conceptual frameworks on the cause-effect relationships (i.e. how do restoration actions change habitat conditions and in turn biota).
Methods/Data: Literature review, conceptual work
Starting: Not specified
Topic: River restoration
Description: Mapping the hydrological, morphological, and biological changes as part of a long-term monitoring. Investigating the long-term changes in the restored river reach of the sand-bed stream "Rotbach".
Methods/Data: Fieldwork
Starting: Not specified
Topic: River restoration
Description: Mapping the input, retention, and decomposition of leafs (as an important process and function of stream ecosystems) in a restored and non-restored section of a sand-bed lowland stream, and investigating its effect on benthic invertebrates and water chemistry.
Methods/Data: Fieldwork, literature review
Starting: Not specified
Topic: Floodplain assessment
Description: Developing factsheets for different types of river floodplains in respect to floodplain biota (related to floodplain habitats).
Methods/Data: Literature review
Starting: Not specified
Contact: H. Jachertz
Topic: Parasitology, ecotoxicology
Description: In natural conditions, fish are exposed to multiple stressors, for example, metal pollution and parasite infection. These factors might have effects on the response of fish to the other. Therefore, it is of importance to take into account parasitism in ecotoxicological risk assessment. The objective of this study is to analyse metal concentrations in chub tissues and the acanthocephalan to quantify the ratio between metal concentrations in the chub and acanthocephalan.
Methods/Data: Labwork
Starting: August 2017
Contact: T.T. Yen Le
Topic: Parasitology, ecotoxicology
Description: Parasites have been considered in assessing metal bioaccumulation. However, the influence of parasites has mainly been evaluated in terms of the capacity of parasites to accumulate metals. Another potential influence of parasites, that has hardly been studied, is that parasites might disturb detoxification mechanisms in the host, such as the induction of metallothionein. The objective of this study is to measure the concentration of metallothionein induced in kidney, liver, and intestine to test if the acanthocephalan affects metallothionein induction in chub.
Methods/Data: Labwork
Starting: May 2017
Contact: T.T. Yen Le
Topic: Parasitology, ecotoxicology
Description: Besides bioaccumulation, subcellular partitioning plays an important role in determining metal toxicity because of the capacity of organisms to detoxify metals. Therefore, it is important to assess the whole chain from accumulation, subcellular partitioning to toxic effects. The aim of this study is to determine Cu concentrations in different subcellular fractions to investigate if Cu toxicity can be explained by the concentration of Cu in the metal-sensitive fraction.
Methods/Data: Labwork
Starting: June 2017
Contact: T.T. Yen Le
Topic: Parasitology
Description: We offer different theses with a focus on aquatic parasites. In the field and lab, the following topics can be investigated:
Methods/Data: Fieldwork, labwork, statistics
Starting: Not specified
Contact: D. Grabner
Internships are also offered as exploratory work or preliminary studies for different Master,- Bachelor- or State Exam theses (please see the respective theses above).
Topic: River ecology
Description: Dissection and labeling of ground beetles, and updating an existing database on ground-beetles (Excel). Introduction to the determination of ground beetles on species level.
Methods/Data: Computer work, labwork
Starting: April 2017
Contact: K. Januschke
Topic: River ecology, river restoration
Description: Determination of ground beetles from samples of three restored and a degraded reach of the Ruhr river. Comparision of the ground beetle communities to detect restoration effects.
Methods/Data: Labwork, statistics
Starting: April 2017
Contact: K. Januschke
Topic: River ecology, river restoration
Description: Woody buffers potentially have many beneficical effects on biodiversity and ecosystem services of rivers besides the well-known and well-studied reduction of nutrient and fine sediment input from agricultural areas. The objective is to compile existing literature and to further develop an existing conceptual model on the effects of woody buffers (Feld et al., 2011).
Methods/Data: Literature review
Starting: Not specified