Long-term monitoring is crucial for assessing anthropogenic impacts such as offshore wind farm (OWF) development, which might alter fish community composition through habitat change and refugium effects. This study demonstrates the value of integrating 12S eDNA metabarcoding with beam trawl sampling for marine fish biodiversity monitoring in the Belgian Part of the North Sea (BPNS). It provides a before-impact baseline assessment for the Princess Elisabeth Island (PEI) zone, a future site for OWF development. eDNA successfully distinguished spatial patterns in fish communities across coastal, transition, and offshore zones and detected rare species such as Alopias vulpinus (Common thresher shark) in the PEI area. eDNA and beam trawl surveys are complementary, with beam trawling remaining effective for demersal species, while eDNA metabarcoding captured more pelagic and rare species. Additionally, two important challenges in eDNA metabarcoding were addressed. Submerging Niskin bottles in seawater effectively reduced field cross-contamination, though further validation via sequencing is needed. A double-sided bead size purification reduced non-target 16S DNA during library preparation but showed no clear benefit in the sequencing output. This research supports the development of standardized, effective, and non-invasive protocols for long-term marine monitoring and contributes to Good Environmental Status under the Marine Strategy Framework Directive.
promotor/supervisor feedback
nothing yet
