Andersen, N.R., Stæhr, P.U., Andersen, K.R., Buur, H, Jakobsen, Hans H., Winding, A. & Sapkota, R. 2023. Havneovervågning af ikke-hjemmehørende arter 2021. Havstrategiens deskriptor 2. Aarhus Universitet, DCE – Nationalt Center for Miljø og Energi, 57 s. - Videnskabelig rapport nr. 534. http://dce2.au.dk/pub/SR534.pdf
This report is part of the Danish marine monitoring program for the period 2021-2026 and involves quantification of non-indigenous species (NIS – including cryptogenic species) in six selected major Danish harbors (Esbjerg, Hirtshals, Frederikshavn, Aarhus, Fredericia and Copenhagen). The project, which is financed by the Danish EPA, aims to register NIS during spring to autumn of 2021, using a suite of conventional techniques (scraping samples, sediment samples, settling plates) and eDNA-based (qPCR) techniques. In total 24 NIS species were found, 17 with conventional and 11 with eDNA methods, four in common for all six monitored harbors. The number of NIS per harbor varied from 7 to 14. Two new NIS for Danish waters were observed (Schizoporella japonica and Sinelobus vanhaareni) in Esbjerg and Copenhagen ports, respectively. Compared with a baseline study from 2017 for the same six harbors, where 32 NIS species were found, we observed 24 NIS of which 15 were also found previously. The report evaluates the applied methods and provides recommendations for future NIS monitoring in Danish harbors.
