Significant Projects
Here we present some selected research topics that our institute has been working on intensively and has already gained significant insights. Some of these topics are also highly relevant in relation to currently discussed issues in society, such as biodiversity and animal welfare:
The TeichLausitz Project
The Lusatian pond landscape is the largest contiguous pond area in Germany, and has a 750-year tradition of carp pond management. Using an inter- and transdisciplinary research approach, the TeichLausitz project is investigating how these ecologically valuable cultural landscapes in the states of Brandenburg and Saxony can be secured for the long term. The focus in this project is both on the conservation of the managed ponds and on the preservation of the associated biodiversity and ecosystem services within Lusatia. In this context, recommendations for the further design of relevant framework conditions and support programmes based on natural, economic and social science studies are to be developed and made available to decision-makers. To accomplish such a complex project broad cooperation is necessary, which is why this project is being supervised and worked on by three scientific institutions (International University Institute Zittau of the Technical University Dresden, Johann Heinrich von Thünen Institute Bremerhaven, Institute of Inland Fisheries Potsdam-Sacrow) and one practical partner (administration of the UNESCO Biosphere Reserve Upper Lusatian Heath and Pond Landscape State Enterprise Saxony Forest). It is particularly important for us to involve the numerous stakeholders in the Lusatian pond farms, such as the pond farmers, representatives of the relevant authorities, associations and other interest groups. The project is divided into seven modules and thus combines scientific expertise and practical knowledge. For a more detailed explanation (in German language) of which modules and tasks our institute is working on, please click here.
A new press article (in German language) on the topic of this project has been published in the Sächsische Zeitung in July 2023!
Pike perch rearing and animal welfare
Due to its popularity with fish consumers and at the same time stagnating yields from capture fisheries, interest in breeding and keeping pikeperch under controlled conditions in tanks and ponds is increasing. Compared to other commercial fish species, however, artificial propagation outside the natural spawning season and feeding with dry feed - two essential prerequisites for aquaculture - are difficult. In recent years, practical methods for solving these problems have been developed at the IfB. Today, we can breed pike-perch at different times of the year without the use of hormones. Pike-perch accustomed to dry feed showed excellent growth at temperatures of 22 - 26°C in rearing trials with extraordinarily high feed conversion rates. These fish reached the marketing weight of about one kilogram after only 14 months - in lakes they need 3 years for this. Studies on meat quality showed no loss of taste in pike-perch from aquaculture compared to wild-caught animals. Now it is important to further refine the rearing protocols that have been developed and to transfer them into practice.
Compliance with animal welfare in fish farming is a socially demanded principle and a matter of course in fish farming at the IfB. Many consumers see animal welfare as an important intangible criterion for making purchasing decisions. The aim of an IfB research project was to develop and verify a model that enables an assessment of animal welfare in the rearing of pike-perch on the basis of animal welfare indices. About 50 potential animal welfare indicators based on the parameters "husbandry environment", "flock" and "individual" were grouped and assessed with regard to their informative value as well as their reliability. By weighting the indicators finally included in relation to each other, an evaluation index was created which can vary from 0.0 (no animal welfare) to 1.0 (best possible animal welfare). The evaluation model developed was tested by means of sample surveys in selected farms. It now offers a basis for the assessment of animal welfare in pike-perch farming, using internationally applied, methodologically uniform, objectively collected datasets. The evaluation model, named Bewertungstool ZWIM 1.0 is available for download to the interested reader (in German language, only).
Reintroduction of large salmonids
Up to the early last century, salmon and sea trout were among the best-known inhabitants of some of Brandenburg's rivers. In the course of progressive industrialisation, discharges of pollutants and cross-building in particular the extinction of these species was brought about within a few decades, because they are demanding in terms of environmental quality. In recent years, improved water quality and also the redesign of weirs and other fish migration obstacles have opened up opportunities for the reintroduction of salmon and sea trout. This has enabled reintroduction of both species to Brandenburg's waters. Meanwhile, every year young fish swim out of the Stepenitz into the Elbe and migrate from there to the Atlantic, where they remain for at least 2 years before returning to their nurseries to spawn. However, the stocks are currently still too small to fully establish themselves without support. Therefore, both the development of the juvenile salmon and the migration of the parents are closely monitored by the IfB and supported by accompanying measures.
Research on the stock situation of the European eel
The European eel has an unusual life cycle. For reproduction, the animals, which have grown up in coastal and inland waters, migrate across more than 6,000 km to the western Atlantic Ocean. After hatching, the eel larvae return to European coastal areas, rivers and lakes. Here, they remain for about ten to twenty years before they embark on the spawning migration, again as the next generation of parent fish. For the past 30 years, eel stocks have been in sharp decline and have now reached an all-time low. The reasons for this development are insufficiently known and also difficult to assess due to the special life cycle. Yet, the eel is not only an important component of fish species communities in domestic waters, but also a highly sought-after species in commercial and angling fisheries. For several years, the IfB has, therefore, been investigating the dynamics of eel populations and the key factors influencing the stocks in Brandenburg's lakes and rivers. This includes measurements of the natural immigration of young eels as well as the outmigration of mature eels. But also studies on condition and state of health during different age stages are necessary. The results are used to develop management plans for the conservation of European eel in the Elbe and Oder rivers' catchment areas.
Use of pit lakes for fisheries purposes
The flooding of former open-cast mines in Lusatia and the Leipzig lowlands will create more than 100 new lakes (pit lakes) in the medium term. In some of these lakes, the IfB is testing the development of typical and economically viable fish species communities. The early years of some lakes are characterised by considerable short-term fluctuations in limnological conditions (i.e. conditions of the water body as an ecosystem) and therefore also in fishing opportunities. For example, in Lake Gräbendorf, which covers 425 ha and is approx. 35 m deep, a considerable change in the fish species community occurred as the pH value fell sharply due to the decline in the available flood water quantities. Stable pH-neutral conditions will only develop in the future. In Lusatia, this scenario will affect a number of larger lakes, which will only achieve more stable conditions after a longer aftercare period with further surface water supply.
If you would like to learn more about our projects, we invite you to take a look at the publications section, where you can find sources of information on a wide range of projects in our IfB publication series: as summaries in the annual reports, or as detailed reports in the thematic issues.