Scaling up Greening the Grey and Eco-engineering Science through partnership with coastal infrastructure asset managers: creating co-benefits for science and operational practice.


The combination of increased storminess, sea level rise and urbanisation will result in the continued proliferation of coastal protection. This will often necessitate hard infrastructure, such as seawalls and rock revetments being placed in coastal settings. UK government strategies state that infrastructure needs to be sustainable, resilient and designed to work with nature. Urban ecosystems, including coastal hard infrastructure, have significantly lower biodiversity than equivalent natural habitats [1]. A growing body of research, however, shows that hard infrastructure can be designed to support biodiversity more akin to that found on natural rocky shores [1,2] while not impact on engineering function[3]. There is now an increasing tool-kit of inexpensive ecological enhancement options which can transform grey infrastructure into more resilient and sustainable components of urban coasts[1,3]. Research in this field is maturing and uptake of these designs in practical engineering projects is increasing, but key research gaps still remain. Working in close collaboration with the project’s CASE partner the Environment Agency, this project will address four key research gaps:

1. Scaling up from experimental studies to operational, whole engineering structure application.
To date eco-engineering research has been at the experimental scale. What is urgently needed is for this research to be scaled up to look at the biodiversity benefits of scaled eco-engineering enhancements. This is now possible as the early experimental scale research has led to eco-engineering interventions being deployed at scale. This scale of research allows us to 1) assess what scale of active ecological enhancement of engineering structures are required to have appreciable ecological benefits and ii) which combinations of rock mass and material properties, and resulting geomorphic features have the greatest ecological benefit using passive ecological enhancement techniques[4]. Additionally, longer timeseries datasets are a gap in eco-engineering science and this project would allow whole-structure monitoring of engineering schemes with passive enhancements (e.g. Hartlepool) 8 years after construction, alongside monitoring of active enhancements undertaken by the Environment Agency (e.g. Elmer Scheme, Natural Resources Wales and Milford Haven Port Authority (e.g. Milford Haven enhancements) and Nature Scotland (e.g. the Wildline Project) schemes all constructed in 2020.

2. Bioerosion – Material choice interactions.
One of the lesser studied topics in eco-engineering is measuring the interactions between biota and rock /concrete materials, where biota often erode rock, helping shape important habitat niches on engineered assets through time (called biogeomorphic ecosystem engineering)[5]. Here field and laboratory experiments will be undertaken on a range of rock and concrete materials (hereafter, materials) commonly used in coastal engineering to quantify differential bioerosion rates. These data would advance ecology and biogeomorphology science, and also help identify which materials are best suited for ecological enhancement in operational applications.

3. Bioeroders as ‘Natural Cleaners’
Some structures, such as access slipways, steps on piers and ferry routes in UK harbours, require routine maintenance to clean these surfaces to remove algae which causes slip hazards for people. These procedures are economically costly and can also be damaging to marine life. What if the biogeomorphology and ecology research on biotic-rock and cross-scalar biotic interactions, can be used to create a biological ‘natural cleaning’ solution – reducing the need for chemical cleaning of these surfaces? Gastropod grazers are known to control algal coverage on natural rocky shores[6], but no attempt has been made to transfer this role into controlling nuisance algae on engineered structures. Here the student will investigate the species, ecological enhancement, spatial arrangement and density of grazer and intervention to best control nuisance algae an in so doing reduce maintenance costs and ecological impacts.

4. Facilitating widespread implementation of eco-engineering in operational practice.
One of the largest eco-engineering challenges is operationalizing the toolbox of eco-engineering interventions into large scale commercial projects. These implementation challenges can happen across the life cycle of a project from conception, through to detailed design, tendering and construction [Naylor et al. 2012]. The student will work with the Environment Agency (case partner) to identify existing policy and practice best practice, as well as implementation opportunities and barriers. This information will be used to co-produce a best practice routemap for improving application in operational practice.


The project will involve elements geomorphology, ecology and social science. Therefore the student will undertake a truly cross-disciplinary PhD.
Objective 1: Standard intertidal monitoring techniques will be used including quadrat counts and SACFOR surveys. In particular, the student will identify biodiversity benefits at the scale of the whole structure by comparing eco-engineered with environmentally similar non-enhanced structures. Where multiple enhancements have been included in a single structure (e.g. Milford Haven) the impacts on beta-diversity will be measured by sampling across microhabitats.

Objective 2: Field and lab experiments will be conducted to determine rates of bioerosion on different material types by a suite of molluscan grazers. Rates of bioerosion will be determined via collection and analysis of grazer skat and stomach contents analysis as well as by repeat structure for motion photogrammetry to measure fine-scale (mm) field weathering of rock surfaces. As metabolic rates and therefore grazing rates increase with temperature the student will explore the impacts of future climate warming on bioerosion rates through faecal pellet analyses in laboratory mesocosm studies.

Objective 3: Working with Milford Haven Port Authority the student will design experiments on a newly installed slipway in Milford Haven to investigate the type of eco-engineering enhancement, species of grazer and density and arrangement of the enhancement and grazers on controlling nuisance macroalgal growth. Grazers will be tagged and monitored to determine fidelity to their eco-engineered habitats. Algal coverage will be determined using a bentho-torch quantify microalgal coverage and quadrats to determine macroalgal coverage.

Objective 4:
The student will work closely with the case partner, the Environment Agency, to evaluate recent coastal engineering projects that have considered and/or implemented eco-engineering approaches to develop a best practice routemap showcasing existing best practice and strategies to support practitioners in implementing eco-engineering more widely on their infrastructure projects.

Project Timeline

Year 1

Literature review (M1-3); development of experimental design for the monitoring of existing schemes in Edinburgh, Hartlepool, Elmer (M4-6); field monitoring of the operational sites (M6-8); sampling design, site selection and arranging permissions for gastropod sampling for the experiments in Obj 2 (M9-12). Attendance of British Society for Geomorphology postgraduate workshop. Writing up the literature review.

Year 2

Installation of field experiments for Obj 2 (M12-15); repeat monitoring of operational sites (M16-18); site visit to conduct baseline surveys for Obj 3 (M19); laboratory experiments for Obj 2 (M20-24) Attendance at the British Society for Geomorphology Annual Conference; submission of paper related to Obj 1.

Year 3

Analysis and write up of Obj 2 and 3 for key journals and working with the case partner to co-produce Objective 4. Implementation. Presentation at the British Ecological Society Annual Conference (M26) and the ICE Coastal Conference (M35).

Year 3.5

Finalise the writing of manuscripts/chapters/best practice routemap; work experience on projects with the CASE partner; submit thesis (M37-42).

& Skills

The student will receive extensive training under the guidance of the supervisory team, which will be complemented by specific training activities to equip the student with the skills and expertise to become an independent researcher in geomorphology and ecology. Specific training in field and laboratory research methods, including field surveying (e.g. SfM), use of mesocosms and programming with Matlab/Python or R for statistical analysis, image processing and data integration as well as field and laboratory work design and instrumentation. These will be complemented by training in core scientific skills (writing, presentation and science communication) and transferable skills (data management, task coordination and exploitation of results with end users). The student will also work with the CASE partner on work package 4 and in doing so learn about the organisational culture and practice in the Environment Agency and in co-producing deliverables with them. The lead supervisor has extensive, award-winning knowledge exchange experience which she will share with the student.

The student will also participate in IAPETUS2 training and events, which will complement the personal training plan. The student will also benefit from the extensive and growing research networks the supervisory team have (e.g. via the Ecostructure project) and get the opportunity to participate in some of these larger externally-funded projects if they wish to do so, to further enhance their future employability and training experiences.

References & further reading

1. O’Shaughnessy, et al. (2019) Design catalogue for eco-engineering of coastal artificial structures: a multifunctional approach for stakeholders and end-users. Urban Ecosystems
2. MacArthur, M. et al. incl. Naylor, L.A. (2019) Maximising the ecological value of hard coastal structures using textured formliners. Ecological Engineering: X, 1, 100002. (doi: 10.1016/j.ecoena.2019.100002)
3. Naylor, L. A. et al. (2017) Greening the Grey. University of Glasgow report. URL: [Accessed 15/01/2020].
4. Macarthur, M. et al., incl. Naylor, L.A. (2020) Ecological enhancement of coastal engineering structures: passive enhancement techniques. Science of the Total Environment, 740, 139981. (doi: 10.1016/j.scitotenv.2020.139981)
5. Naylor, L.A., Coombes, M. A. and Viles, H. V. (2012) Reconceptualising the role of organisms in the erosion of rock coasts: A new model. Geomorphology, 157-15, pp. 17-30. (doi: 10.1016/j.geomorph.2011.07.015)
6. Coleman RA, et al. (2006) A continental scale evaluation of the role of limpet grazing on rocky shores. Oecologia 147:556–564.

Further Information

For informal enquiries, or if you are interested in applying, contact Prof Larissa Naylor (

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