Assessing quality of flowing waters with DNA analyses

The quality of waters can be assessed using of the organisms occurring therein. This approach often results in errors, because many species look alike. Therefore, new methods focus on DNA analyses instead.

Biologists at the Ruhr-Universität Bochum (RUB) have optimised the process so that they are now able to identify many organisms at once in a quick and reliable manner using short DNA sequences.

Industry, agriculture and human settlement put a strain on bodies of water; some organisms cannot survive due to the changing conditions in streams and rivers. Accordingly, their existence sheds light on the quality of the habitat.

However, the number of experts able to identify the small animals on the basis of their appearance is in decline; only a few junior researchers are active in this field. RUB researchers from the Department Animal Ecology, Evolution and Biodiversity help preserve expert knowledge.

For this purpose, they are creating a database in collaboration with the "German Barcode of Life Project": in the first step, qualified experts identify the water organisms based on their appearance. Subsequently, a short characteristic segment of the animals' genome -- i.e. the barcode -- is decoded and fed into the database. Someone who wishes to find out which species are represented in a body of water, takes a water sample, sequences the DNA of the organisms contained therein and matches it against the database.