Coral reef ecosystem collapse: constraining rates of biological and physical erosion. PhD in Geography (NERC GW4+ DTP)

Lead Supervisor
Prof Chris Perry, Department of Geography, College of Life and Environmental Sciences, University of Exeter

Additional Supervisors
Dr Ken Johnson, Department of Earth Sciences, Natural History Museum
Dr Barend van Maanen, Department of Geography, College of Life and Environmental Sciences, University of Exeter
Dr Lorenzo Alvarez-Filip, National Autonomous University of Mexico (UNAM), Mexico

Location: University of Exeter, Streatham Campus, Exeter, EX4 4QJ

This project is one of a number that are in competition for funding from the NERC GW4+ Doctoral Training Partnership (GW4+ DTP). The GW4+ DTP consists of the GW4 Alliance of research-intensive universities: the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five unique and prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory. The partnership aims to provide a broad training in the Earth, Environmental and Life sciences, designed to train tomorrow’s leaders in scientific research, business, technology and policy-making. For further details about the programme please see http://nercgw4plus.ac.uk/

For eligible successful applicants, the studentships comprises:

- A stipend for 3.5 years (currently £15,009 p.a. for 2019/20) in line with UK Research and Innovation rates
- Payment of university tuition fees;
- A research budget of £11,000 for an international conference, lab, field and research expenses;
- A training budget of £3,250 for specialist training courses and expenses.
- Travel and accomodation is covered for all compulsory DTP cohort events
- No course fees for courses run by the DTP

We are currently advertising projects for a total of 10 studentships at the University of Exeter

Project Background

The growth and development of tropical coral reefs is determined both by the rate at which skeletal calcium carbonate is produced (mainly by corals), and the rate at which this carbonate is degraded or removed by biological and physical processes. The balance between these production and erosion processes is described as a reefs carbonate budget. In the Caribbean, where coral reefs have suffered severe declines in coral cover over the past few decades due to multiple human impacts and climate change, the carbonate budgets of most reefs are increasingly dominated by erosional processes. This is leading to loss of reef growth potential and structural erosion. Methodologies to quantify these carbonate budget states now exist, but whilst there is reasonably good data on rates of carbonate production to inform calculations, data on the rates at which different species erode reef material and on rates of physical removal are sparse. This PhD project aims to address these key knowledge gaps.

Project Aims and Methods

The aim of this project is to address current data gaps relevant to constraining rates of biological and physical substrate erosion on Caribbean coral reefs, and to quantify their impacts on Caribbean reefs. This will be undertaken using a combination of field and experimental approaches, with a specific focus on the shallow-water reefs of the Mexican Caribbean in the proximity of the UNAM Lab at Puerto Morelos. Specifically the student will: (1) undertake experiments to quantify rates of substrate erosion by endolithic sponges. This is projected to be based on ex-situ experiments, the design of which the students will take a major role in developing; (2) Assess how different sponge species utilise different substrate types and space on the reef – to inform models of changing sponge erosion rates as reef communities and substrates change; (3) Undertake experiments to quantify rates of endolithic microbioerosion between substrates/habitat spaces – to inform estimates of rates of reef-wide microborer erosion; and (4) Quantify rates of physical reef framework movement and removal – to inform predictions of rates of reef growth potential. The student is expected to have significant input into experiment design, with some flexibility to steer the key area of focus on these processes depending on individual research interests.