Dr C Trueman, Dr E Hunter
Applications accepted all year round
Funded PhD Project (UK Students Only)
About the Project
Ecosystem changes associated with warming seas are driven by the physiological responses of individual organisms. Although critical in predicting population responses to climate change, the extent to which individuals are able to mitigate temperature effects by modifying behaviour and metabolic response is unknown. Metabolic scope is the difference between an organism’s standard and maximum metabolic rate. For a given median water temperature, metabolic scope may be increased behaviourally by reducing total (field) metabolic rate (FMR) by seeking colder water, by foraging less or by reducing growth. The extent to which populations maintain the capacity to vary metabolic scope is an unknown but critical concept for predicting species’ responses to climate change. Measuring marine fishes’ FMR in natural habitats is a major scientific challenge currently limiting predictions of fish physiological responses to climate change. Using a new biogeochemical proxy for FMR based on otolith stable carbon isotope composition, we will explore the metabolic response of individual fish to decadal temperature change. Focussing initially on plaice, we will make use of an extensive multi-decadal archive of otolith samples to provide the first record of spatial and temporal differences in FMR plasticity across a species’ thermal range.
The FMR proxy developed in lead supervisor Trueman’s group at Southampton is based on a comparison of carbon isotope compositions of otolith aragonite, ambient dissolved inorganic carbon and dietary carbon. This project will first extend theory associated with the proxy by taking advantage of existing otolith material from a previous experiment where plaice were raised under known conditions. Subsequently the extensive Cefas historical otolith archive will be used to measure relative FMR between individuals and populations of plaice in regions experiencing different absolute temperature and differential rates of temperature change.
The graduate school of the National Oceanography Centre, Southampton (GSNOCS) is one of the largest postgraduate schools in Europe, and provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at NOCS, with frequent exchange with project partner Cefas. Specific training will include: Otolith age reading, and other sclerochronological analyses; micro-sample preparation, stable isotope ecology, fisheries ecology, and science-policy exchange. All equipment needed to section, mill and analyse otolith stable isotopes are present in NOCS and Cefas, and all samples are in-house within the Cefas archive. However, there will be opportunities to join Cefas cruises to gain experience of ship-board fisheries ecology.
Funding Notes
This project is funded from a NERC Industrial CASE Studentship award and is only available to UK citizens or people resident in teh UK for the past 3 years.
References
Kalish JM. 1991. 13C and 18O isotopic disequilibria in fish otoliths: metabolic and kinetic effects. Marine Ecology Progress Series 75: 191-203.
Darnaude A.M., A.M. Sturrock, C. Trueman, D. Mouillot, EIMF, S.E. Campana & Hunter E., 2014. Listening in on the past: what can otolith δ18O values really tell us about the environmental history of fishes? PLoS ONE 9(10) e108539. doi: 10.1371/journal.pone.0108539
Trueman, C.N., Chung, M-T and Shores, D. 2016. Ecogeochemistry potential in deep time biodiversity illustrated using a modern deep-water case study. Phil. Trans. Roy. Soc. B 371: http://dx.doi.org/10.1098/rstb.2015.0223