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

Abstract

This thesis establishes the northern fulmar (Fulmarus glacialis) as a sentinel species for the health impacts of plastic exposure, owing to its high levels of plastic ingestion. This is a significant expansion beyond its role as a plastic bioindicator used to monitor environmental plastic pollution in the North-East Atlantic. This work presents a multifaceted examination of how ingested plastic contaminants influence health through analytical chemistry, genomics and molecular biomarkers. The findings from this ecotoxicological investigation have implications for both other wildlife and human health. Plastics and their effects on marine and human health are discussed, and the fulmar as a sentinel for these effects is described. Fulmar sentinel sample selection was delineated, and included feathers, blood and liver tissue. 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.

This thesis is embargoed until 31 July 2027.

Date of Award	Jul 2024
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	NERC QUADRAT
Supervisor	Gary Hardiman (Supervisor)