PhD defence: Amalia Aikaterini Mailli

Thesis title:

The potential of metagenomics and metatranscriptomics based on next generation sequencing for the taxonomic profiling of benthic communities

Trial lecture topic:

From genes to ecosystems: novel approaches for marine biodiversity monitoring

Evaluation Committee:

• Professor Florian Leese, Faculty of Biology, University of Duisburg-Essen, Germany
• Researcher Claudia Junge, Marine ecosystems and resources department, Institute of Marine Research (IMR)
• Professor Steinar Daae Johansen, Faculty of Biosciences and Aquaculture, Nord University

Supervisory Committee:

• Main supervisor: Emeritus Professor Truls Moum, Faculty of Biosciences and Aquaculture, Nord University
• Co-supervisor: Professor Henning Reiss, Faculty of Biosciences and Aquaculture, Nord University
• Co-supervisor: Researcher Lars Martin Jakt, Faculty of Biosciences and Aquaculture, Nord University

Thesis summary:

Benthic environments support diverse eukaryotic communities vital to marine ecosystems. Traditionally assessed through morphological taxonomy, these communities can now be studied more efficiently using DNA-based methods. This thesis compared metabarcoding, metagenomics, and environmental mRNA sequencing to evaluate benthic diversity and ecological patterns. Metabarcoding produced results consistent with morphology, while metagenomics and mRNA analyses were constrained by database gaps and false positives. mRNA showed potential for real-time community assessment but was less effective in detecting aquaculture impacts. Integrating multiple databases improved annotation capacity by 20%.

Overall, the study demonstrates the promise of molecular approaches for benthic monitoring while underscoring the need for stronger bioinformatics support and improved sampling design.gnet for å oppdage påvirkning fra akvakultur. Integrering av flere databaser forbedret annoteringskapasiteten med 20 %. Studien viser samlet sett at molekylære metoder har stort potensial for overvåking av bunnmiljøer, men understreker samtidig behovet for bedre bioinformatisk støtte og forbedret prøvetakingsdesign.