Biodiversity in the seas – how to recognize it?


Who counts the species, tells the names...? (© Thünen-Institut/Reinhold Hanel)

The diversity of fish species is also reflected in our menus – but this is not always desired. From time to time fish originating from illegal or unregulated fisheries enters the European market. This could be prevented by unambiguous species identification and origin verification (traceability). In this regard, genetic fingerprinting is a helpful tool, especially for processed products like filets or preserved food. At the Thünen Institute we have a unique collection of DNA samples of Atlantic fish species. In an ongoing project, we are developing a reference database to help monitoring and consumer protection agencies to identify illegal imports of fish and fisheries products. The coastal waters of West Africa rank among the most important fishing grounds for the European market. At the same time, they are among the most predominant areas of illegal fisheries worldwide and, hence, are especially prone to overfishing and the destruction of natural areas.

It is crucial for the monitoring of fishery activities to be able to trace the origin of fisheries products. An unambiguous determination of the species – and ideally also of the geographic origin – is especially difficult for processed products. The consequences are mislabeling, concealment of illegal fisheries and uncertainty for consumers. For example, in the port of Hamburg the inspection of a container with declared imported monkfish filets was found to contain puffer fish filets instead, which are similar in appearance but comparatively inexpensive.

Molecular genetic methods permit an unambiguous species determination and, to a certain extent, also inference of geographic origin, even for processed fisheries products. We are currently developing a reference database to identify the most important fish species from Western Africa. This database can be considered as a valuable tool to increase consumer safety and detect illegal fishery activities.