Environmental DNA (eDNA) Project: Understanding pelagic by-catch
For some time there has been concern about the level of accidental killing of salmon by pelagic vessels at sea during migrations from and to their rivers of origin. Previous research has shown that salmon are caught as a by-catch in pelagic vessels fishing for species such as mackerel and herring, but the extent of such catches is not known.
The AST and University College Dublin are running an innovative project to develop and pilot a pioneering technique to assess the presence or absence of salmon DNA on board ships using environmental DNA (eDNA). The method involves the analysis samples from nets or on-board water samples to identify salmon DNA shed from the fish through scale loss or from slime/bodily fluids. The eDNA collected may also provide valuable information on the origins of salmon in the by-catch, which will greatly add to our knowledge of salmon migration and distribution patterns in the ocean. Other applications for similar eDNA probes include the identification of the presence of Gyrodactylus salaris in freshwater samples or the presence of the organism on items such as anglers tackle, boats and canoes. eDNA also has the potential to assess the presence of fish farms escapees.