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 Sarah Holmes

Sarah Holmes

PhD student



After transferring from Queen Mary University of London, I graduated in 2015 with a BSc in Geography (with proficiency in Spanish) from the University of Exeter.

My undergraduate dissertation at Exeter led me to conduct 8 weeks of lab work at Bangor University’s School of Ocean Sciences at the invitation of Professor Chris Richardson (Head of SOS). During the stay, I learned techniques for preparing and processing bivalve shells for sclerochronology - the study of the growth lines on bivalve molluscs analogous to dendrochronology. The final project entitled “A sclerochronology of the English Channel – using the annually-resolved growth increments of Glycymeris glycymeris to infer recent marine palaeoenvironment” produced the first ever sclerochronology of the English Channel and added to the limited number of bivalve proxies in the UK and worldwide.

In my final year at Exeter I was offered a PhD with the University of Exeter, Bangor University and CEFAS. The aim of the project is to better understand the shelf sea environment with the aid of ecosystem models and the proxy records of long-lived bivalve molluscs.


BSc Geography with proficiency in Spanish (University of Exeter)

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Research projects

Project Title: Using annually resolved bivalve records and biogeochemical models to understand and predict climate impacts in coastal oceans

Supervisors: Dr Paul Halloran, Prof. Chris Perry (Exeter University), Dr Paul Butler (Bangor University) and Dr Johan van der Molen (CEFAS).

Funding Body: NERC and CEFAS (NERC Industrial CASE Studentship)

Project Description:
The shelf seas are disproportionally productive compared to the open ocean, sustaining over 90% of global fisheries. It is therefore very important to understand both past and future processes in these coastal oceans, especially in lieu of climate change, which threatens eutrophication, anoxia, ocean warming and more. Biogeochemical or ecosystem modelling has the capacity to reconstruct shelf sea processes, both hindcasting and forecasting, but spatial and temporal limitations in observational data of the ocean is restricting our ability to test model accuracy.

This PhD study aims to create and use proxy records of the bivalve mollusc Arctica islandica in the North Sea to validate and improve the benthic component of ecosystem models, in particular the CEFAS version of the European Regional Seas Ecosystem Model (ERSEM). The research may then be able to advance predictions of how future shelf seas will respond to climate change, influencing the advice given to policy-makers and stakeholders as well as contributing to the wider modelling, sclerochronology and climate/ocean science community.

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