Biodiversity and migratory species

Expertise

The European eel is classified as endangered (© Thünen-Institut/FI)

Of the existing 33,000 fish species about 7,000 are used for human consumption, and the trend is upwards. Fish species often vary only in a few characteristics, with the result that they are often only distinguishable by experts. Nonetheless, when aspiring high product quality and consumer protection, as well as a back-tracking of fish and fish products for stock protection, a definite identification of fishes and a confirmation of their origin is required.   

Controls are also needed for processed fish products, such as filets and tinned fish: fake labelling must cease. At the Thünen Institute we have expertise in fish identification, laboratory analytics and fish genetics. We develop genetic markers for species identification and for stock separation of important model species. These include sprat and herring as well as icefish and tuna. Of particular interest and great importance are migratory species. Many fish species make long and exhausting migrations to reach spawning grounds and find feeding areas, and some of them cover enormous distances and large obstacles. Fish species that migrate between fresh and marine waters, so-called diadromous species, are often particularly vulnerable to human impacts. They are put under pressure by river constructions and fragmentation of habitats as well as by over-fishing and climate change.  

This leads to special challenges for stock management, often associated with an international coordination of protective measures and sustainable use strategies. We engage ourselves with a wide variety of questions regarding the biology, ecology, behavior, protection and use of ecologically and economically important fish species. One focus of our work is on the investigation of the different life stages of the European eel (Anguilla anguilla). Its stock has been regarded as outside safe biological limits for years, and Anguilla thus classified as endangered. By means of field and laboratory studies, we aim at a better understanding the European eel life cycle  and  the factors and mechanisms that influence the stock. Thereby we strive to establish the basis for a sustainable stock management of this species.