Species introductions and invasions are considered as a major threat to ecosystem functioning due to non-native species’ potential to alter autochtone communities’ structure and function.
The round goby (Neogobius melanostomus) is an introduced fish in the Baltic Sea and is known for its high feeding rate. Adult round gobies have shown a clear preference for small bivalves and gastropods, while native species, such as the flounder (Platichthys flesus), have a wider food spectrum. The establishment of round gobies could therefore have a different effect on lower trophic levels than native fish species would have. Predation effects of juvenile round gobies remain unknown and to date, there are no experiments comparing the differential effects of round goby to native benthivorous fish on invertebrate communities in the Baltic Sea. This is an important factor to consider to be able to draw any conclusions of whether this introduced fish will have a different effect on the benthic community structure and functioning, compared to native species.
Metabarcoding procedures will be used in order to assess meiofaunal taxonomic diversity. Visual morphological taxonomic identification is usually employed to identify organisms but this traditional methodology is time consuming and do not preserve most soft-bodied meiofaunal organisms, thereby generating biased richness results. DNA-based methods will allow the identification of most meiofaunal species with high level of taxonomic resolution, with very low amount of sample biomass, and without bias associated with observer or organisms’ body size.