A systems-level analysis of the impacts of plastic-associated endocrine disrupting chemicals on the Northern Fulmar (Fulmarus glacialis)

Following this background, the relationship between extent of plastic ingestion and bioaccumulation of harmful endocrine-disrupting chemicals (EDCs) was assessed, such as polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) in liver tissue, using gas and liquid mass spectrometry. Next, high-throughput sequencing (HTS) was performed for the first time on this key species. This included de novo hepatic transcriptome assembly and subsequent transcriptomic analyses to quantify gene expression in the livers of birds with and without ingested plastics.

These elucidated the biological pathways perturbed by these contaminants. Further, the application of reduced representation bisulphite sequencing (RRBS) to DNA from blood and feather samples provided insights into DNA methylation changes associated with plastic exposure. Additionally, this thesis pioneers the quantification of corticosterone levels in fulmar feathers to assess long-term stress responses.

Crucially, corticosterone levels were compared in birds with different plastic exposure or ingestion levels. This comprehensive approach not only confirms the northern fulmar’s capacity as an effective sentinel, but also enhances our understanding of the molecular and systemic effects of plastic exposure. The research highlights the pressing need for comprehensive and coordinated environmental policies, including the advancement of an International Plastics Treaty, to mitigate the widespread and deleterious effects of plastic pollution.

By evidencing the fulmar’s pivotal role in detecting broader ecological and health ramifications from plastic contamination, this thesis makes a significant contribution to the field of ecotoxicology. It calls for the strengthening of monitoring and regulatory frameworks, essential for safeguarding marine biodiversity and promoting human health, underscoring the interconnectedness of ecosystem and public health.<br><br><i>This thesis is embargoed until 31 July 2027.</i>