Impacts and co-benefits of fishing on tropical blue carbon storage

Overview

Enhancing the sequestration and storage of carbon in natural marine ecosystems (termed blue carbon) may provide an eco-friendly solution for combatting atmospheric CO2 increases. The fundamental characteristics of blue carbon habitats also encourage the provision of a wealth of other eco-benefits, such as the support of diverse fish populations. In turn, this ecological foundation provides high ecosystem resilience and has immense socioeconomic value, such as supporting local-international fishing industries.

The tropical reef system, including coral reefs, seagrass meadows and mangrove forests, is one of the most productive and diverse on Earth, but each habitat harbours varying levels of blue carbon storage capacity. Fish population structure may be one of the key drivers of this  herbivorous grazing for example, is known to impact carbon sequestration and storage rates in seagrass meadows. Fishing activities therefore may have both positive and negative effects on carbon storage through habitat disturbance and alterations to the ecological trophic structure. Understanding these complexities, under present-day and future climate projections, is vital for creating robust management plans and in encouraging cooperation between stakeholders.

The aim of this project is to determine the impact of artisanal fishing activities on the blue carbon storage capacity of tropical reef systems, with a focus on the Caribbean. This will be conducted using a multidisciplinary approach that combines ecological and biogeochemical methods.

Methodology

The PhD student will have the opportunity to collect coral reef, sediment and water samples from sites within the Caribbean (SCUBA diving is optional) for carbon storage (i.e. long-term lockdown into sediments) and sequestration (i.e. C uptake via photosynthesis) quantification, using state-of-the-art analytical facilities available at the Lyell Centre. Advanced ecological survey techniques (e.g. 3D habitat modelling), combined with historical records of ecological diversity available from Operation Wallacea, will enable the relationship between fish population diversity and blue carbon to be determined. Field-based experiments, such as excluding fish herbivory activity or simulating destructive fishing activities, will enable their role in blue carbon processes to be determined. Should Covid-19 restrictions still be in place, physical distancing in the field and off-peak visits will be possible, supplemented by the considerable volume of historical biodiversity data available from Operation Wallacea. Projected changes in the co-benefit relationships between blue carbon and fish population dynamics will be modelled using IPCC climate projection scenarios, enabling incorporation of the project data into future management plans at the local to regional scale.

Project Timeline

Year 1

Literature review, field & analytical technique development, summer fieldwork

Year 2

Sample analysis & interpretation, laboratory experiments, summer fieldwork, presentation at a national conference

Year 3

Sample analysis & interpretation, write-up for publication, presentation at an international conference

Year 3.5

Writing-up of results and completion of thesis, submission of papers for publication

Training
& Skills

Project support

The facilities, equipment and expertise available within the institutions and supervisory team provide a combination of world-leading field, analytical and laboratory capability and technical support that ideally fits this PhD project, maximising the expert training that will be available.

This project will equip the student with a range of skills, including fieldwork, analytical science, numeracy and translation of science for wider audiences. Specific research skills will include:
– Organic and inorganic carbon quantification
– In situ ecological surveys and experimentation
– Ecological modelling
– Big-data analysis
– Experimental design
– Environmental statistics

PhD student support

The Lyell Centre has a large research student cohort that will provide peer-support throughout the studentship, including participation in the annual post-graduate research conference. All project supervisors are also highly research-active. The PhD student will interact with all members of their research groups through lab-group meetings at the Lyell Centre, University of Glasgow and Operation Wallacea, providing an opportunity to learn about other techniques and research areas which may be applicable to their research. Additionally, the supervisors are all based in research-active departments that span a broad range of ecological, environmental and geoscience research, exposing the scholar to a range of other research areas. Active participation in these research groups will provide the opportunity to discuss cutting-edge topics in the field, review recent papers and to present current research plans to academics with a common research interest in an informal and supportive atmosphere. The PhD student will also have the opportunity to undertake a placement with Operation Wallacea, providing work experience within a non-academic organisation.

Where required, and to maintain continued professional development, the PhD student will be supported to attend specialist courses directly aligned to the project:
– Sediment carbon analyses via mass spectrometry
– Data visualisation
– Potentially a field first aid course in the first 6 months of the project may be available
– Potentially scientific diving courses
– Analytical training for each piece of instrumentation required for analyses.
– Attendance to transferable skills training such as data management, scientific writing and science communication. These are provided for free within Heriot-Watt University’s Research Futures Academy.

References & further reading

Fourqurean, J.W. et al 2012. Seagrass ecosystems as a globally significant carbon stock. Nature geoscience, 5(7), pp.505-509

Johnson, R.A. et al 2017. Blue carbon stores in tropical seagrass meadows maintained under green turtle grazing. Scientific Reports, 7(1), pp.1-11

Mao, J. et al 2020. Carbon burial over the last four millennia is regulated by both climatic and land use change. Global Change Biology, 26(4), pp.2496-2504

Further Information

In the first instance, enquiries should be directed to the primary supervisor, Dr Heidi Burdett (h.burdett@hw.ac.uk). Please indicate why you are interested in this project and attach your CV to the email.

For eligible candidates, funding is available to cover tuition fees, stipend and research costs. However, please note that this project is in competition with others for funding, and success will depend on the quality of applications received.

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