Application of novel genetic tools for fisheries conservation and management

Abstract

Anthropogenic pressure on the environment has increased, threatening ecosystem structure and function. Aquatic environments are disportionally impacted by this, with climate change expected to amplify negative impacts in the future. Therefore, it is vital that aquatic communities are effectively monitored, so mitigation measures can be put in place. However, traditional monitoring methods are time-consuming, expensive, and require taxonomic expertise. Genetic tools can overcome these difficulties, whilst offering further insights. Therefore, this thesis aimed to apply genetic tools to different challenges, demonstrating novel applications of these tools in aquatic environments, for the conservation and management of species present.

I used eDNA-based methods and qPCR to investigate species in aquatic environments. I created two novel eDNA assays, for a marine invader, Crepidula fornicata, and for a threatened native species, the European oyster, Ostrea edulis, thus adding to the tools available for monitoring and/or conservation and subsequent management of these species. Results generated illustrated that tidal state and season can impact results, but also that eDNA analyses may not be suitable for all species. The use of eDNA for routine monitoring of an invader, Dreissena polymorpha was investigated, with eDNA successfully detecting D. polymorpha in known areas but did not find new populations. These findings demonstrate that eDNA methods should remain as supplemental measures, until uncertainties have been addressed. Finally, I demonstrated the importance of genetic analysis in hybridisation zones. I applied a multiplex qPCR assay to presumed native Mytilus edulis individuals. Findings indicate that, for the first time, an M. edulis/M. trossulus hybrid was discovered in Northern Ireland, with additional M. edulis/M. galloprovincialis hybrids and M. galloprovincialis individuals discovered for the first time in Carlingford and Larne loughs, emphasising the importance of genetic tools. Ultimately, this thesis summarises how we can utilise existing genetic tools for conservation and management of aquatic environments.

Date of Award	Dec 2024
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	NERC QUADRAT
Supervisor	Sarah Helyar (Supervisor), Alex Douglas (Supervisor) & Louise Kregting (Supervisor)