Mitigating the effects of climate change, emerging disease and invasive species on native amphibian populations in the UK

Primary supervisor: Dr Robert Puschendorf (University of Plymouth)

Secondary supervisor: Professor Trent Garner, (ZSL Institute of Zoology). Email: Trent.garner@ioz.ac.uk

Additional supervisors:

Dr John Wilkinson, (ARC Trust). Email: John.Wilkinson@arc-trust.org

Dr Manuela Truebano (University of Plymouth)

Dr Richard Billington (University of Plymouth).

Dr Stephen Price (University College of London). Email: s.price@ucl.ac.uk

Project description

Amphibians are the most threatened group of vertebrates, with global declines driven by and associated with emerging infectious disease, invasive species and climate change (North et al. 2015; O’Hanlon et al. 2018; Pounds et al. 2006). 

Two emerging infectious diseases severely impacting amphibian populations are chytridiomycosis, caused by a novel lineage of the fungus Batrachochytrium dendrobatidis (Bd; O’Hanlon et al. 2018), and ranavirosis, caused by a group of viruses from the Iridoviridae family (Price et al. 2014). 

To mitigate emerging disease-driven amphibian declines, we need to understand host-pathogen interactions. Key to pathogen success are reservoir hosts which serve as a pathogen source, but do not develop any signs of the diseases (Garner 2018). 

These reservoir host are a consistent source of the infective stage of pathogens when the susceptible amphibian host populations decline and are pushed towards extinction; in many cases these reservoir hosts are invasive amphibian species.

Wales, UK, has an ideal amphibian system to study these host-pathogen interactions, with both native, declining populations of amphibians as well as newly discovered smooth and alpine newts, which are an invasive species to the area. 

Climate change has already affected ranavirus disease dynamics in wild frogs, but it is currently unknown how future changes will affect disease dynamics in other hosts, or how amphibian community composition will impact outcomes (Price et al. 2018).

We seek a candidate who is self-motivated and interested in developing analytical skills in ecology, immunity, spatial epidemiology, climate modelling and experimental biology. 

You will become part of a team of researchers based at 4 UK HEIs with the ultimate aim to develop conservation strategies to effectively conserve the endemic amphibian fauna through climate change and emerging disease. Indirectly, the student will work with researchers at ZSL, UCL, Imperial College, QMUL, Liverpool and DICE embedded in a larger project on amphibian declines and emerging disease.

Applicants must meet the eligibility requirements of the ARIES DTP. The successful candidate should have the scientific ability and motivation to do the best possible quantitative research in the field as well as in the laboratory. Flexibility to live in Plymouth and spend time in London as well as Wales for fieldwork.

Research questions and methodology

Bd and ranavirus are the two main amphibian pathogens linked to population declines (e.g. Rosa et al. 2017). These pathogens thrive under different temperature regimes (Price et al. 2018; Woodhams et al. 2008) and are more likely to cause disease die-offs in the presence of a reservoir host – due to elevated/high pathogen load. 

The overarching aim of this project is to develop effective conservation strategies for endemic amphibian fauna threatened by invasive species, emerging disease and climate change, which will likely act synergistically with devastating effects (Pounds et al. 2006; Price et al. 2018). 

This project will understand patterns in the field with an annual field season in Wales during the spring and summer to understand current host-pathogen dynamics and ecological interactions between native and invasive host.

To understand the potential effects of the rapid shifts in the climate we are set to experience, the candidate will have to design experiments to examine the relationship between infection dynamics, the presence of invasive host and temperature in the survival of susceptible endemic hosts. 

Amongst the suite of tools available are the quantification of host microbiomes and antimicrobial peptides, both linked to amphibian survival when challenged by these pathogens in other systems (Campbell et al. 2018; Voyles et al. 2018).

Based on both field and experimental data and to understand how a changing climate will affect this system the student will then explore how host range and survival would shift using future climate change projections. 

Based on all the work mentioned above the candidate will use structure decision making to develop a comprehensive strategy to mitigate the impacts of infectious disease and invasive host to these native amphibian systems (Canessa et al. 2018).

Training and collaborations

Training will be provided on a wide breadth of topics including ecological methods quantifying amphibian host location, densities, survival and techniques to assess and quantify infection dynamics in the wild. 

Through the collaborative network, the student will develop skills in molecular diagnostics, immunology and pathology, spatial epidemiology, and climate modelling. 

The student will have the opportunity to learn how to extract and purify antimicrobial peptides and challenge assays to quantify pathogen growth when exposed to this first line of defence in amphibians. 

Microbiology techniques can also be learned, such as 16s RNA and ITS metagenomic bar-coding to identify the amphibian microbiomes and allow to explore if differences in these communities correlate with host infection and survival.

Fundamental to running experiments the students will learn captive husbandry and in vitro pathogen growth and exposure. Learning about Home Office-licensed experiments and applying the 3Rs will be a necessary and added skill learned. 

The student will work directly with the CASE partner and with the support of a wider Network across Plymouth, IoZ, Imperial and UCL to develop a comprehensive conservation and management plan for native amphibians under the above-described threats.

Funding

This project has been shortlisted for funding by the ARIES NERC Doctoral Training Partnership. Undertaking a PhD with ARIES will involve attendance at training events.

ARIES is committed to equality & diversity, and inclusion of students of any and all backgrounds. All ARIES Universities have Athena Swan Bronze status as a minimum.  

Applicants from quantitative disciplines who may have limited environmental science experience may be considered for an additional three-month stipend to take appropriate advanced-level courses.

Usually, only UK and EU nationals who have been resident in the UK for three years are eligible for a stipend. Shortlisted applicants will be interviewed on 26/27 February 2019.  

For further information please see www.aries-dtp.ac.uk or contact us at aries.dtp@uea.ac.uk.