Coral reef ecosystem collapse: constraining rates of biological and physical erosion

A diver examining a coral reef

This PhD project will investigate the current data gaps relevant to constraining rates of biological and physical substrate erosion on Caribbean coral reefs.

The studentship is part of the Great Western Four+ Doctoral Training Partnership, funded by NERC and starts October 2020.

Apply for this course

Applications for this PhD are processed via the University of Exeter online application service.

Application deadline: 6 January 2020

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.
  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.


Applications are primarily open to UK residents only (minimum residence of 3 years excluding time in further education), however, a limited number of full studentships are also available to EU residents. Students from EU countries who do not meet the residency requirements may still be eligible for a fees-only award but no stipend.  Applicants who are classed as International for tuition fee purposes are not eligible for funding.

All applicants need to comply with the registered university's English-language requirements.

Applicants should have obtained or be about to obtain a First or Upper Second Class UK Honours degree, or equivalent qualifications gained outside the UK. Applicants with a Lower Second Class degree will be considered if they also have a master's degree. Applicants with a minimum Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.

How to apply

Applications for the PhD are processed via the University of Exeter online application service. You will need to include:

  • CV
  • Letter of application outlining your academic interests, prior research experience and reasons for wishing to undertake the project.
  • Transcript(s) giving full details of subjects studied and grades/marks obtained. This should be an interim transcript if you are still studying.
  • If you are not a national of a majority English-speaking country you will need to submit evidence of your current proficiency in English.
  • Two References (applicants are recommended to have a third academic referee, if the two academic referees are within the same department/school).

The deadline for applications is 6 January 2020.

Shortlisted candidates will then be invited to an institutional interview. Interviews will be held between 10 and 21 February 2020.

Visit the University of Exeter website for more information.

Any questions?

You are encouraged to contact potential supervisors by email to discuss project-specific aspects of the proposed research at an early stage.

If you have any questions about the project please contact

Main supervisor: Prof Chris Perry


University of Exeter

Main supervisor: Prof Chris Perry

Co-supervisor: Dr Barend van Maanen

The Natural History Museum

Co-supervisor: Dr Ken Johnson

National Autonomous University of Mexico (UNAM), Mexico

Co-supervisor: Dr Lorenzo Alvarez-Filip


Perry CT & Alvarez-Filip L (2019) Changing geo-ecological functionality of coral reefs in the Anthropocene. Functional Ecology. 33, 976-988.

Perry CT, Steneck RS, Murphy GN, Kench PS, Edinger EN, Smithers SG, Mumby PJ (2014) Regional-scale dominance of non-framework building corals on Caribbean reefs affects carbonate production and future reef growth. Global Change Biology 21: 1153-1164.

Perry C.T., Murphy G.N., Kench P.S., Edinger E.N., Smithers S.G., Steneck R.S., Mumby P.J. (2014) Changing dynamics of Caribbean reef carbonate budgets: emergence of reef bioeroders as critical controls on present and future reef growth potential. Proceedings of the Royal Society B. 281: 2014-2018

Perry C.T., Edinger E.N., Kench, P.S., Mumby P.J., Murphy G., Steneck, R.S. and Smithers S.G. (2012) Estimating rates of biologically driven coral reef framework production and erosion: a new census-based carbonate budget methodology and applications to the reefs of Bonaire. Coral Reefs. 31: 853-868

Perry, C.T., Spencer, T. & Kench, P. (2008) Carbonate budgets and reef production states: a geomorphic perspective on the ecological phase-shift concept. Coral Reefs 27: 853-866

Great Western Four+ Doctoral Training Partnership

Joint PhD training partnerships between the Natural History Museum and the Great Western Four, Bath, Bristol, Cardiff and Exeter universities.

Funded by