Abstract
The European lobster (Homarus gammarus) supports valuable inshore fisheries throughout the North Atlantic, yet uncertainties surrounding recruitment, connectivity, and the effectiveness of conservation measures continue to challenge sustainable management. This thesis investigated the stock structure and recruitment dynamics of European lobster populations along the west coast of Ireland, with a particular focus on the long-running v-notching programme on Inis Oírr, Aran Islands. Microsatellite DNA profiling, genetic tagging, parentage analysis, and biophysical larval dispersal modelling were integrated to evaluate population connectivity and quantify the reproductive contribution of protected females. A robust microsatellite marker panel was developed and validated for genetic tagging and parentage assignment, providing a scalable tool for long-term fisheries monitoring. Genetic analyses revealed high levels of genetic diversity and limited evidence of population subdivision among sampled regions, consistent with substantial connectivity along the Irish west coast. Parentage analyses identified 717 high-confidence offspring assignments linked to v-notched females, representing approximately 12% of the 5,915 lobsters screened. These assignments provided direct evidence that v-notched females contribute to realised recruitment across multiple cohorts and locations. Assigned offspring were detected not only around Inis Oírr but also in Galway Bay, Connemara, Clare, and neighbouring regions, demonstrating that recruitment benefits generated by local conservation measures can extend beyond the area in which broodstock protection occurs. Biophysical larval dispersal modelling supported these findings, indicating extensive larval-mediated connectivity along the Irish west coast, while also identifying areas of local retention and interannual variability in dispersal patterns. Together, the genetic and modelling results demonstrate that v-notching is an effective conservation measure that contributes directly to recruitment in European lobster populations. The findings highlight the importance of cooperative regional management and demonstrate the value of integrating genetic tagging and biophysical modelling to support evidence-based fisheries conservation and stock assessment.Thesis is embargoed until 31 July 2029.
| Date of Award | Jul 2026 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Sponsors | Marine Institute |
| Supervisor | Rose Hynes (Supervisor) & Paulo Prodohl (Supervisor) |
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