Master- and Bachelor Theses

Research topics: Fisheries management and fish biology / Fisheries induced evolution / Social economic issues around Fisheries

The Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) is an institution of the Leibniz Association and part of the Berlin Research Network (FVB). The IGB (www.igb-berlin.de) is the largest research center for inland waters in Germany. It combines fundamental research with precautionary studies as the basis for sustainable management of our waters and examines the structure and function of aquatic ecosystems under near-natural conditions and the influence of multiple stressors. Additionally, the IGB advises policymakers, the economy, and the public on water management issues and trains scientific personnel.

The IGB is connected to all three Berlin universities (Humboldt University of Berlin, Free University of Berlin, Technical University of Berlin) through joint professorships, and in this role, it plays a significant part in student education.

The IGB, Department of Biology and Ecology of Fishes, working group for Integrative Fisheries Management, simultaneously serves as the Department of Integrative Fisheries Management at the Life Sciences Faculty of Humboldt University of Berlin (www.ifishman.de), led by Prof. Dr. Robert Arlinghaus, is looking for committed students from the fields of fisheries science, biology, economics and social sciences related to natural resource use, psychology, geography, or agricultural sciences for the completion of

study project work, bachelor’s theses, and master’s theses in the area of fisheries science and related fields.

The department head, Prof. Dr. Robert Arlinghaus, can supervise student theses from the HU programs Fish Biology, Fisheries & Aquaculture, and Integrated Natural Resource Management at the Life Sciences Faculty of Humboldt University of Berlin.

The assignment of theses as externally supervised theses at other institutions, faculties, and universities in Germany and abroad is generally possible in consultation with the home institutions.

The following research topics are currently offered at the IFishMan working group (www.ifishman.de) as master’s or bachelor’s theses. Some of the projects can also be designed as study project work and are accordingly marked. Many projects can be organized to be compatible with lecture periods, for example, by collecting field data on selected days during the semester, which can then be analyzed in the last semester after course completion. For many topics, data is already available, allowing for immediate analysis. This is a crucial advantage for those aiming to complete their degree within a semester (six months). For field topics involving data collection, it is advisable to plan data collection throughout the semester. If interested, please contact the mentioned members of the working group or the group leader, Prof. Dr. Robert Arlinghaus.

Supervision: For all projects, Prof. Dr. Robert Arlinghaus is the main supervisor for the strategic direction of the work. The individuals listed under each topic take on daily supervision.

Note: Some of the following topics are described in German but can, of course, be addressed by English-speaking students. If proficiency in German is a requirement, this will be marked for each topic.

Who are the topics suitable for?

All topics are open to fish biologists, biologists, psychologists, and agricultural scientists from Berlin or other federal states or abroad. Applicants can expect to be intensively involved in an active working group at the IGB and Humboldt University of Berlin (www.ifishman.de). Candidates are expected to have a research interest. Previous bachelor’s, diploma, and master’s theses from our working group can be viewed at www.ifishman.de. With sufficiently high-quality work, we aim for joint publication of the results. Students will be integrated into all institute and working group processes. We aim to provide a workspace for each student at the IGB or at HU. Participation in international conferences is generally facilitated and funded.

If you are interested please sent CV and transcript of records to Prof. Dr. Robert Arlinghaus (arlinghaus[at]igb-berlin.de, Tel. 030-64181-653).

Note: You may also suggest your own topics that relate to the research interests of the IFishMan-Lab.

TOPICS

Fisheries biology, and fisheries and biodiversity management

1. Bachelor thesis or Master thesis: Impact of size selection on collective behavior, cognition and catchability to different fishing gears

We have selected zebrafish (Danio rerio) as a model organism over five generations for size, simulating size-selective harvesting. Now we would like to ask – is there an evolutionary response in collective behavior, cognition, aggression and foraging rate? Does fishing change these traits? And are the fish evolutionary adapted to high pressure more difficult to capture by trawling, trapping and angling? The work means experimental lab work in the aquaria hall at IGB to compare how the different selection lines perform. One immediate topic of interest is whether evolutionary adaptations to size selection have altered the catchability to hook and line angling.

Supervisor: Dr. Tamal Roy

2. Study project or Bachelor thesis or Master thesis: A literature review on key ecological factors affecting fish stocking outcomes

We have recently proposed that the outcome of stocking in terms of generating additive effects to increase fish stocks sizes is driven by four key factors: degree of natural recruitment, ecological and genetic adaptation to stocking, stocking size and handling and stocking stress (Arlinghaus et al. 2015, 2016). This project is meant to constitute a rigorous literature review to collect and examine the empirical evidence for this conceptual model of fish stocking success in published literature. The project can start any time.

Supervisors: Prof. Dr. Robert Arlinghaus

3. Study project or Bachelor thesis or Master thesis: A literature review on determinants of catch and release mortality for fishes of relevance to Germany

This study shall update Hühn and Arlinghaus (2011) to identify the key determinants of the lethal and sublethal impact of catch release in recreational fisheries and derivation of best practice guidelines.

Supervisors: Fritz Feldhege and Robert Arlinghaus

4. Study project, bachelor thesis or master thesis: Which fishes do we catch? Catchability of fishes, vulnerability to angling and the timidity syndrome caused by recreational fisheries

Students that must be avid anglers can develop field projects to ask questions of the relative catchability of different fishing lures types or other gear configuration (e.g., with our without a steel leader in predatory angling), the impact of angler experience and gear configuration on catch rates and injury of fish in recreational angling, the relevance of water body type on catchability as well as the response of predators to angling in the context of the timidity syndrome, i.e., reduction in catchability after encountering with a lure through learning (see Arlinghaus et al. 2017 Fish and Fisheries). We currently seek students particularly to study

Alteration of catch per unit effort in predatory fish (perch, pike) in response to heavy fishing pressure
Learning of fish to avoid capture after exposure to specific highly obvious (from a fish perspective) lure types (e.g., spinners, spinnerbaits)
Do fish predators switch prey fish after being exposed to fishing with that particular prey type (e.g., from perch to roach)

Supervisors: Dr. Ryo Futamura, Prof. Dr. Robert Arlinghaus

5. Master thesis: The ecology of the individual – have we underestimated the importance of large fish in fisheries management?

This is a literature review to collect all information we have on the relevance of individual large fish for fisheries, e.g., in the context of sexual selection, fecundity, population dynamics and for fishing quality.

Supervisors: Prof. Dr. Robert Arlinghaus

6. Master thesis: Hyperallometry in size-fecundity relationships in freshwater fish and the relevance of large fish

Barneche et al. (2018) published a paper in Science that reports that the increase in the fecundity with size is not linear, but exponential in marine fish. This challenges the traditional view and elevates large fish to mega spawners. What is the evidence for this in freshwater fish? The topic can be extended to a comprehensive analysis of the role of large fish for population ecology in fish.

Supervisor: Prof. Dr. Robert Arlinghaus

7. Master thesis: A meta-analysis on the ecological impacts of common carp (Cyprinus carpio)

A literature review with a meta-analytical component (estimation of quantitative effect sizes) on the ecological impacts of carp should be completed. The question is under which conditions does carp negatively impact macrophytes, turbidity etc.

Supervisor: Prof. Dr. Robert Arlinghaus

8. Master thesis: Behaviour and nutrition of trophy European perch in lower reaches of the River Rhine in the Netherlands

Together with collaborating partners at University of Wageningen and the Dutch Sport Fishing Association we are interested in learning about the large range movement behaviours of trophy perch and the nutrition and diets of these fish. The topic shall take place in a hotspot of contemporary recreational fishing for freshwater predators, the Haringvlied in the Netherlands in the lower reaches of the River Rhine.

Supervisor: Prof. Dr. Robert Arlinghaus

9. Bachelor or Master thesis: Impact of groundbaiting on water quality and eutrophication

In this work we would like to measure impacts of groundbaiting by boilies and other materials used in roach and bream angling on water quality and methane release and concut an assessment of the eutrophication potential of groundbaiting by balancing introductions of nutrients and removals through fish harvest. Work will be completed combining experimental angling sessions and laboratory work with sediment cores collected from Lake Müggelsee in collaboration with biochemists at IGB.

Supervisor: Prof. Dr. Robert Arlinghaus

Sozialwissenschaftliche und sozio-ökonomische Themen

Social science and socio-economic topics

The following topics are particularly suited for students of the Integrated Natural Resource Masters in the Faculty of Life Sciences at Humboldt-Universität zu Berlin, particularly those with a background in psychology, human geography, political sciences, agricultural economics, recreation studies, economic sciences. But also fisheries, human geography or environmental science students with an interest more on the human side of fisheries management are highly encouraged.

10. Masterarbeit: Impact of the closure of the recreational cod angling fishery in the western Baltic Sea on angler behavior and angler well-being using a difference-in-difference approach

The recreational cod fishery in the western Baltic Sea was closed to harvest as of January, 1, 2024 because the stock collapsed. We have collected data from more than 600 recreational cod anglers before and after the collapse and have asked for behavioural adaptations and other consequences. In this thesis, the data should be analysed in terms of what the closure means for recreational anglers and how they responded psychologically, emotionally and behaviourally to the drastic change.

Betreuung: Postdoc Carsten Riepe and William Arlidge

11. Masterarbeit: Soziodemografische Einflussfaktoren auf die Zuschreibung menschlicher Eigenschaften zu Tieren im Kontext der Fischerei und Angelfischerei (Sociodemographic factors affecting the attribuition of human traits to animals, i.e. anthropormophiszing)

Grundlage dieser Themenbearbeitung sind bereits vorliegende Daten aus einer repräsentativen Bevölkerungsbefragung mit über 1000 in Deutschland wohnhaften Bürgern der Allgemeinbevölkerung (vgl. Riepe & Arlinghaus 2014, Berichte des IGB). Erklärt werden soll die Neigung von Menschen, Tiere zu anthropomorphisieren, d.h. ihnen menschliche Gefühlszustände zuzuschreiben. Dazu wurde für eine Reihe von Tieren (einschl. Forelle) erhoben, ob die Befragten ihnen z. B. Schmerz- oder Leidensfähigkeit, die Fähigkeit zum logischen Denken oder den Besitz eines Bewusstseins unterstellten, ob sie glaubten, dass diese Tiere dieselben moralischen Rechte wie Menschen haben sollten usw. Außerdem wurde eine Fülle soziodemografischer Basisdaten einschließlich Freizeitverhalten erhoben sowie u. a. Einstellungen zum Hobbyangeln, zur Natur, zur Umwelt und zu Tieren, die als erklärende Merkmale dienen können. Es gibt keine vergleichbaren Daten aus dem deutschsprachigen Raum. Die Arbeit kann unmittelbar angegangen werden.

Betreuung: PostDoc Dr. Carsten Riepe

12. Study project or Bachelor thesis: Differences in angler perceptions towards catch-and-release and other aspects assessed by social media and content analysis of published media

Exemplified with a few key countries (e.g., UK, USA, Canada, Germany) the candidate is expected to use social media analysis examining how anglers discuss catch-and-release in different cultures. Insights into trends can also be derived from google analytics and other web-based analyses. It is also possible to do a trend analysis from the analysis of feature articles from angling media (Blinker, Fisch & Fang) and from Google Search Volume data. German language is mandatory.