Mussels (bivalves of the family Mytilidae) are incredible animals with a long fossil history. For millions of years, populations of mussels have been able to withstand pounding waves by attaching themselves to the seafloor using threads that are one of the strongest materials found in nature. Deep-water reefs or beds of mussels build up in part because a bank of shells forms a favourable site of attachment for these threads, and juveniles are also able to survive by hiding between the stacked shells. Modern bank-forming mussels are a dominant feature of cooler, high latitude seas, so it is interesting that their Jurassic counterparts – the central subject of this proposed study – inhabited tropical coral reefs. Jurassic shallow marine sedimentary rocks containing fossil mussels are abundant in the UK, including sites on the Isle of Skye and Helmsdale in northern Scotland, in Antrim in Northern Ireland, and an extensive belt of outcrop stretching from north Yorkshire, through the midlands and Oxfordshire, to Dorset on the south coast of England. This project will examine time series assemblages of fossil mussels, to understand potential threats and stressors in the deep past, and so inform the management of mussel species around the UK and elsewhere today.
The main causes of physical damage in the Jurassic were likely to have been storms. The British Jurassic sediments were deposited at tropical latitudes where hurricanes were frequent, and these will certainly have had the power to rip up and destroy colonies of mussels. Sedimentary logging will help tell us whether hurricanes were the main or a common cause of mussel colony death, and we will also be able to examine whether colonies were able to re-establish themselves following storms. Mussels are also prone to predation but those that survive an attack can repair the shell, leaving a scar. These are all evidence of stressors that would impact mussel populations in the past, and also occur today.
Shells will be examined for physical damage, including evidence of storm damage or active predation, using ‘cutting edge’ optical and electron microscopy as well as micro-CT techniques. The student will also use electron microscopy to examine shell geochemistry for signs of heavy metal contamination from river run-off. Where preservation of original material allows, palaeotemperatures and palaeo-salinities will be deduced using a combination of carbonate oxygen stable isotopes and clumped isotope palaeothermometry. Finally, the student will document temporal changes in fauna including other molluscs, using statistical approaches to determine whether any organisms commonly accompanied expansion or decline in mussel colony growth.
In addition to fieldwork training, the student will receive extensive training in geochemistry and in modern microscopy and visualisation techniques, supported by their completing an internship with CASE partner CarlZeiss.
This research will help to protect economically and environmentally important living mussel populations by revealing the natural environmental factors that affect their growth, abundance and extinction.
Candidates should have (or expect to achieve) a minimum of a 2.1 Honours degree in a relevant subject.
• Apply for Degree of Doctor of Philosophy in Geology
• State name of the lead supervisor as the Name of Proposed Supervisor
• State ‘QUADRAT DTP’ as Intended Source of Funding
• State the exact project title on the application form
Application closing date is 12:00pm (GMT) on 31 January 2019. Applications received after this time will NOT be considered. Additionally, incomplete applications will NOT be considered. When applying please ensure all required documents are attached:
• All degree certificates and transcripts (Undergraduate AND Postgraduate MSc-officially translated into English where necessary)
• 2 References (Academic, where possible)
Informal inquiries can be made to Dr A Brasier ([email protected]
) with a copy of your curriculum vitae and cover letter. All general enquiries should be directed to the Postgraduate Research School ([email protected]
The start date of the project is 1 October 2019.