Application of DNA-based methods for detection of non-indigenous species (NIS) in harbours
Accurate monitoring is a key prerequisite to limit the spread of non-indigenous species among harbours. To this end, HELCOM and OSPAR developed a port survey protocol to monitor non-indigenous species. This protocol is customized for morphological species identification of the sampled organisms.
While such traditional survey methods require species identification upon visual inspection of each sampled individual organism, they heavily depend on taxonomic expert knowledge. The identification of smaller species often requires examination under a microscope. Alternatively, species can be distinguished based on their unique DNA sequence. Such species-specific DNA barcodes can be read from DNA extracted from bulk samples consisting of many species without prior sorting (so-called meta-barcoding).
In GEANS, we will use DNA-based methods to improve traditional NIS monitoring in harbours and render it more cost- and time-efficient as well as more accurate. Using the HELCOM/OSPAR protocol as a baseline, we will investigate to which extent morphological examination can be complemented or replaced by meta-barcoding. Since organisms will not be examined individually, but simultaneously from a bulk sample, identification will be more time- and therefore also more cost-efficient. In addition, we expect a significant improvement in detection power for non-indigenous species that are difficult to distinguish from similar native or other non-indigenous species. This particularly applies to planktonic larval stages, which are often impossible to identify at species level using morphological examination.
While focusing on the North Sea region, the methods we apply are highly generic and can readily be transferred to other use cases worldwide. As such, our efforts to improve NIS monitoring will also improve standardization at the international level.